Introduction by Alison Marshall
Book of the Tigris (or Book of the River) is a letter Baha'u'llah wrote to a Babi who had asked him about the truth of reports attributing miracles to Baha'u'llah and other Babis. The tablet is, for the most part, a discussion on the subject of miracles and, in particular, the miraculous effect a new revelation has on the world, which Baha'u'llah illustrates by likening it to the effect the Tigris flood waters have on the river's hinterland.
There is debate over the exact year the tablet was written. However, what is known is that the tablet was written between about 1857, when Baha'u'llah wrote the Hidden Words, and 1861, when Baha'u'llah began to reveal his station as He Whom God Will Make Manifest. This conclusion is based on the fact that, in the tablet, Baha'u'llah quotes the first Arabic Hidden Word but is not open about his station.
Nader Saiedi, in his article Concealment and Revelation in Baha'u'llah's Book of the River, gives the background to why the tablet was written:
"Although we do not know the precise date when the tablet was written, we do know something about the context of its revelation. In a long tablet written around 1861 (Mazandarani, Asraru'l-Athar 5: 312–44), Baha'u'llah informs us about his relation to the Babi community in the period between 1856 and 1861. Based on this tablet we know that, as early as 1856, there was a serious debate within the Babi community concerning Baha'u'llah's station. Many of the Babis had noted Baha'u'llah's extraordinary spiritual and moral authority and some even perceived that he was the Promised One of the Bayan. This caused considerable envy and opposition on the part of some of Baha'u'llah's enemies, who threatened to kill his supporters and even prohibited other Babis from traveling to Baghdad. At this time Baha'u'llah's enemies were accusing him of rejecting the Bab, his Mirrors, and the Bayan. In response to this agitation, for a few years Baha'u'llah discouraged some of his Babi followers from making the pilgrimage to Baghdad, eventually allowing visits around 1859.
It is in this context of confusion, rumors, accusations, and animosity that Baha'u'llah wrote the Book of the River in response to the questions of a Babi named Javad (probably Javad-i-Kashani, who became a Baha'i), who asks Baha'u'llah about rumors of miracles that had been attributed to him and to other prominent Babis. From Bahá'u'lláh's response in his tablet, it becomes clear that Javád considers miracles extremely important as justification of Bahá'u'lláh's spiritual authority and even feels miracles to be a necessary demonstration of divine power—to force the powerful and learned leaders of humanity to recognize and submit to the Cause of God. He has trouble understanding how divine dominion can be present when no miracles have occurred." 
The tablet begins abruptly with Baha'u'llah responding directly to the rumours about miracles. He states that any rumours of miracles attributed to him are fabrications put about by his enemies. However, those attributed to the Bab and the Mirrors (that is, prominent followers of the Bab) are true. Having said that, Baha'u'llah quickly goes on to make the point that what God revealed in the Bayan is the universal and conclusive proof for humanity. The verses of God in the Bayan are the universal proof because all humanity can access them equally. The trouble with miracles is that they are witnessed by only one or more people and so cannot constitute a universal proof. Therefore, if anyone has witnessed a miracle, as Javad claims, then that is from the mercy of God for them, but the greatest proof is the verses.
In paragraph 2, Baha'u'llah states that the miracles attributed to the prophets should not be denied just because they defy human reason. Human reason is not the standard by which we should judge such things. He argues that everything on earth was invisible to humans before they took notice of it. He gives the example of the sun. To someone who had never seen the sun before, a description of it from someone who had seen it would seem miraculous. The point is that what appears to us to be a 'miracle' by a prophet is just an occurrence that we don't understand. In paragraph 3, Baha'u'llah goes on to say that all things are the miracles of the prophets and he cites several passages from the Qur'an in support, which point out that God created us, provided for us, and caused us to grow out of the earth; and created the heavens and earth, sent down the waters and calmed the mountains. Hence everything relies on God's power for its existence.
Baha'u'llah goes on in paragraph 4 to address the argument that, if the miracles attributed to the prophets of old really did occur, then they must occur in modern times as well. The implication of the argument is that, if there are no miracles in modern times, then there weren't any in ancient times either. But Baha'u'llah rejects this logic, arguing that just because something happened in days past doesn't mean it has to happen today. He gives the example of an epidemic that used to break out once every 30 years but which had not appeared in recent years. The principle works both ways, he says: things happen in modern times that did not occur in ancient times.
In paragraph 5, Baha'u'llah addresses directly the issue that appears to be on the mind of his correspondent: why doesn't a miracle occur that is so wonderful it demonstrates beyond doubt the truth of the Babi religion? Baha'u'llah responds with a complex analogy between the spiritual 'flood' of a new divine revelation and the physical flood of the Tigris River. The analogy runs over paragraphs 5 to 8. The implication seems to be that the miracle Javad is seeking does indeed occur, but that only those who understand the process can see it happening. The Book of Certitude contains detailed discussion on how revolutionary spiritual changes take place under the noses of those who don't see them even though their lives are shaped by them.
Baha'u'llah describes how, when the Tigris floods, its waters rise up and flow over the surrounding land, sweeping away everything in their path. He emphasises that the effects of the flooding are determined entirely by the river, which doesn't heed the cries of those who are destroyed. And he emphasises the flood's egalitarian quality in that it destroys everything that gets in its way, whether it's a mansion or a shack or a rich person or a poor one. The exception is a building capable of withstanding the force of the waters due to its inherent strength. However, the flooding has positive consequences as well as destructive. If a person was to dam the waters, this would not only flood land behind the dam but irrigate land that was once arid, causing it to turn green.
Baha'u'llah asks his correspondent to see the effects of the new revelation on the world in the same way as the flood waters. Just as the river does as it pleases, God does as he pleases with the effects of a new revelation. It sweeps across the world wiping out everything and everyone that stands in its way, apart from those strong enough to withstand it. In other words, it removes the structures, customs and leaders of now outdated religions and systems of thought. Ironically, though, these people 'die' from burning thirst rather than drowning because they refuse to accept the new religion - "neglecting even so much as to take a sip from it". Those with the capacity to withstand the power of the flood, or dam its waters or otherwise hold the water in some way, such as in the case of a valley, are able to benefit from the new life the waters bring. The effect of the flood on each person will depend on that person's situation or spiritual capacity - some will take advantage of it and place themselves in such a way as to benefit from it, while others, in refusing to see it, will be swept away.
In paragraph 8, Baha'u'llah also uses the imagery of the sun shining in a mirror to illustrate the differences in the spiritual capacities of people. He asks Javad to think of the revelation as a sun and the souls as mirrors. One ray from the "pre-existent sun" shines out and reflects in the hearts, or mirrors, of the people. The image of the sun reflected in each mirror differs according to the inherent nature of the mirror. Some reflect it faithfully and others will reflect a distorted image to some extent and some may not reflect it at all. "For some mirrors stand exalted in their nature and sublime in their aspirations, whereas others stoop in the baseness of their rigidity and their descent into obliteration." Baha'u'llah suggests to Javad that he develop sharp insight so that he can grasp the subtle truths Baha'u'llah is trying to covey. If he was able to understand them, he would no longer be concerned with what other people said or be disturbed by it.
Baha'u'llah often uses in his writings the imagery of the sun and the mirror. Another good example of it is found in paragraph 12 of the Commentary on a Verse of Rumi. In this paragraph, the ray of the sun comes from the divine name "the Self-Sufficient". The passage shows, not only how that one ray takes different forms in the various mirrors, but also how those differences result in contradictions and conflict in the world:
"For instance, consider the divine name, "the Self-Sufficient." In its own kingdom, this name is unified. But after its effulgence in the mirrors of human existence, the effects of that effulgence appear in each soul according to that soul's exigencies. For instance, in the generous it appears as generosity, whereas in the miserly it takes the form of avarice. In the ill-omened it becomes abasement, and in the blessed it appears as good fortune. For in the condition of poverty, souls and what is in them are concealed. For example, the generosity and avarice of someone who does not possess a single penny is hidden. Likewise, in such a condition his good or bad fortune would as yet be impossible to discern. After becoming self-sufficient, every soul shows forth what is within it. For instance, one might expend what he possesses in the path of God. Another might organize war materiel and arise to engage in battle with the truth. One might safeguard others to the point where he denies his wealth to himself and his family. Consider how from one effulgence so many different and contradictory things appear. But before that effulgence all these souls were subdued, concealed and languid. With one ray from the sun of the name, "the Self-Sufficient," how he has resurrected these souls and made visible and manifest what was hidden within them! If you contemplate this utterance with the eye of insight, you will become aware of hidden mysteries."
In outlining the parable of the Tigris, Baha'u'llah has given Javad a new way of looking at revelation and the 'miracle' of God's intervention in the world. God doesn't intervene by disrupting the laws of nature (although sometimes it may appear to humans that this happens); instead, he sets in motion an invisible spiritual power that wipes away the old and nourishes the new. The flow is scrupulously fair: it affects everyone whether high or low and it impacts on people according to their character and deeds. The process is invisible to all except those who have insight and can take advantage of it. Hence, at the beginning of paragraph 9, Baha'u'llah asserts that the most important thing a person can do is recognise and obey the manifestation; that is, see the life-giving waters and drink them. The manifestations Baha'u'llah is referring to are "the most exalted countenance" (the Bab) and "his station upon the throne after him" (Baha'u'llah). Baha'u'llah gives Javad a short prayer emphasising the ideas he has covered about the true nature of miracles: the power, sovereignty and triumph of God, and the fact that we know nothing about God except what God has taught us via the manifestation.
In paragraph 10, Baha'u'llah goes on to recommend to Javad a saying from the life-giving waters, which will help him gain spiritual self-sufficiency and attain eternal life. The saying Baha'u'llah offers is the first Arabic Hidden Word: "Possess a pure, kindly and radiant heart, that yours may be a sovereignty ancient, imperishable and everlasting." He extols the saying in lofty language: "a light that is not extinguished, a treasure that is not exhausted, a raiment that does not wear out, and a splendor over which no curtain is drawn". He describes it as the greatest counsel he could give to Javad and explains that it is the path that will lead Javad to "the possessor of the throne" (that is, the manifestation).
In an e-mail message to the discussion list Talisman 9, dated 9 June 2000, Juan Cole posted a short commentary on the first Arabic Hidden Word, which helps to clarify its meaning. His literal translation of the Hidden Word is: "O Son of Spirit: The beginning discourse is this: Possess an excellent, good, and illumined heart, so that you will accede to an eternal, everlasting, unending and preexistent kingdom."
"O Son of Spirit (Ya ibna 'r-ru:h.)
then it goes on to say that in the beginning of the discourse (fi awwal al-qawl) [is this:] that one should possess an excellent (jayyid), good (hasan), and illumined (munir) heart (qalb), so that one might acquire a kingdom (mulk) that is everlasting, immortal, pre-eternal, and pre-existent (da:'im, ba:qin, azal, qadi:m).
Son of "spirit" states that human beings have a spiritual and not just a material genealogy. The Arabic word "spirit", ru:h., is cognate of the Hebrew ruach, which bears a similar meaning.
With regard to the attributes of the heart, 'excellent' implies of high quality, whereas 'good' has connotations of being morally good. That the 'heart' or emotions can also show forth 'excellence' has been argued by Goleman in his book on emotional intelligence. Illumination implies an openness to reflecting the divine emanations into this world. So the three essential qualities are excellence or high quality, moral goodness, and ability to radiate the divine light.
The result of these three things is the destruction or collapse of time. da:'im and ba:qin refer to something everlasting, which will never end. Azal refers to something that existed before time began. And qadi:m also refers to something that is pre-existent or uncreated (as the Qur'an was held to be by Sunnis). So eternality stretches in both directions, from before time to infinity, and when the heart acquires these attributes it enters this kind of transcendent timelessness."
In this way, Baha'u'llah teaches Javad that the way to attain his spiritual goal is by achieving a particular state of heart. Again, you find the miraculous here, because, somehow, by attaining a pure heart, one collapses time and arrives at a transcendent and timeless kingdom. This idea of finding the eternal by purifying the heart is a fundamental principle of Baha'u'llah's revelation, and he repeats it in various ways time and again throughout his writings.
In the last paragraph, Baha'u'llah asks Javad to testify to the station of various leading figures in Babism. After testifying that there is no god but God, he is to make the following testimonies:
These testimonies must be seen in the historical context in which Baha'u'llah was writing. He had not yet declared himself to be He Whom God Will Make Manifest, and so the Baha'i religion had not yet begun. Therefore, believers were to testify to the Bab, He Whom God Will Make Manifest and leading Babi figures.
In his Concealment and Revelation in Baha'u'llah's Book of the River, Nader Saiedi argues that the "Living Countenance" refers to Baha'u'llah:
"The meaning of the title "Living Countenance" becomes obvious from the Báb's and Bahá'u'lláh's writings: the Living Countenance refers to the return of the Báb (who is the Most Exalted Countenance), but after his own martyrdom, and in a living form. This is clearly a reference to the famous statement of the Báb: "Verily, I am He that liveth in the Abhá Realm of Glory!" (Innany ana h.ayyun fi'l-ufuqi'l-Abhá), a statement quoted frequently by Bahá'u'lláh. In other words, the Living Báb, or the Living Countenance, is "Abhá" (Bahá)." 
Finally, I wanted to comment on the debate between Juan Cole and Nader Saiedi over the meaning of a phrase in paragraph 7, which Juan Cole has translated as "But what shall I say? I make no claim to a Cause." Juan Cole has argued on the basis of this translation that, at the time Baha'u'llah wrote Book of the Tigris, he did not consider himself a manifestation of God. Nader Saiedi has argued that Juan Cole has translated the passage incorrectly, saying that the phrase Baha'u'llah uses is a Persian idiom meaning "Yet, alas, I am disinclined to approach any matter" - in other words, disinclined to say any more on the subject.  The dispute comes down to the meaning of the Persian word "'amr", which can be translated as 'divine Cause', or simply 'affair' or 'matter'.
Recently, Moojan Momen published a paper called Messianic Concealment and Theophanic Disclosure, in which he puts forward another, and to my mind convincing, interpretation, which reconciles the two positions. He looks at the meaning of the word "'amr" in the Qur'an and the Book of Certitude and concludes that it refers to the right of the new manifestation to demand that believers abandon their old religion and adopt the new one. At the time Baha'u'llah wrote Book of the Tigris, he had not yet declared himself as the new manifestation and so there was no obligation on believers to recognise him. Hence, he made no claim to a 'Cause'. Moojan Momen explains:
"If we now take these points back to the disagreement between Cole and Saeidi, the critical distinction that becomes evident in connection with the meaning of the word amr is the distinction between that of merely being the bearer of a revelation and that of imposing upon people the obligation of abandoning the previous revelation and accepting the new revelation. Revelation (wahy) and amr are thus two separate conditions which do not necessarily co-exist. It is possible to have wahy without amr (although not, I think, amr without wahy). In other words, it would appear that for a period of time while was he was in Baghdad, Baha'u'llah was the conscious bearer of a revelation but that he chose not to openly declare this fact and thus impose upon the people the necessity of choosing whether to accept his new revelation or not. During the entirety of the Baghdad period, therefore, the amr of the Bab held sway - the obligation of people was to accept and follow the religion of the Bab." 
On 26 October 2001, Juan Cole sent a message to the discussion list Tarjuman, conceding that Moojan Momen's interpretation was correct. 
 Nader Saiedi: "Concealment and Revelation in Baha'u'llah's Book of the River" in The Journal of Baha'i Studies 9.3.1999 pp. 30-1, found at the Baha'i Studies site. Note that this article contains a full commentary on the tablet.
 Baha'u'llah: Commentary on a Verse of Rumi, paragraph 12, found on this site.
 Peter Smith: A Concise Encyclopedia of the Baha'i Faith (Oxford: Oneworld, 2000) p 285.
 Baha'u'llah: Commentary on the Light Verse, translated by Stephen Lambden, found at Hurqalya.
 Nader Saiedi: "Concealment and Revelation in Baha'u'llah's Book of the River" p 47.
 Juan Cole's commentary on his translation and responses to Nader Saiedi are found at the H-Baha'i site.
 Nader Saiedi: "Concealment and Revelation in Baha'u'llah's Book of the River" p 35.
 Moojan Momen: "Messianic Concealment and Theophanic Disclosure" in Online Journal of Baha'i Studies Volume 1 (2007) p 75, found at the Baha'i Studies site.
 Many thanks to Sen McGlinn for informing me of this.
For further reading on the subject of miracles, see Mirza Abdu'l-Fadl Gulpaygani: Miracles and Metaphors, translated and annotated by Juan Cole. (Los Angeles: Kalimat Press, 1981)