A river in a dream

In the long vision that Samura ibn Jundub reported, the Prophet ﷺ passes two rivers in a single night, and they could not be more different. The first runs red like blood. A man swims in it, and each time he swims back to the bank a second man puts a stone in his mouth. The second flows across a city built of gold and silver bricks, white as milk, and men who are half beautiful and half ugly are told to throw themselves in, and come out in the best shape (Bukhari 7047). Same word, nahr; opposite meanings.

That is the first thing a river teaches, and the sources make the rest of the entry follow from it: a river on its own tells you very little. What it carries, where it flows and what you do in it tell you the rest.

What the angels said about each river

Inside the vision the Prophet ﷺ was given the meaning of each scene, and it is worth reading what was and was not explained. The swimmer fed with stones is the eater of usury (Bukhari 7047, and the shorter telling in Bukhari 2085 calls the water a river of blood). That is a named sin attached to a named image. The milk-white river is explained differently: the angels do not interpret the river at all, they interpret the men, who mixed a good deed with a bad one and whom Allah forgave. The river is what the scene shows doing the washing, and the ugliness drops away in it.

A reader should be careful with this hadith for a reason the text supplies itself. It is a prophet's vision, with angels guiding him and explaining each stop. Ibrahim treated his own dream as a command he had to act on (Qur'an 37:102), while the Sunnah puts an ordinary believer's good dream at one part of 46 of prophecy (Bukhari 6989), which is a different standing. So you should not take Bukhari 7047 as a key that turns every red river in your sleep into a verdict on your income. Its use is to show how the tradition itself reads: by the substance in the river and the people in it. The full vision is told in the longest dream in the Sunnah.

Rivers of reward and rivers of provision

The Qur'an's commonest picture of a river is Paradise: gardens "beneath which rivers flow" (Qur'an 2:25), the righteous placed among gardens and rivers (Qur'an 54:54), and 4 kinds named in Qur'an 47:15: water that does not alter, milk whose taste never changes, wine that is delicious to drink, and purified honey. The Prophet ﷺ added that the Sayhan, the Jayhan, the Euphrates and the Nile are all among the rivers of Paradise (Muslim 2839).

On earth the same image is provision. Nuh tells his people to ask forgiveness of their Lord, who will send rain and give them wealth, children, gardens and rivers (Qur'an 71:10-12). So a clear river running through a garden or a house has a double footing, as reward and as provision, and that is why we read it at the favourable end. The footing is for the image, though, and never for a promise: the hadith about the 4 rivers describes real rivers, and no text tells us a dream of them shows anyone's destination.

A river as a test, a rescue and a boast

The Qur'an has 3 more rivers, and they point in other directions. Talut tells his soldiers that Allah will test them with a river: whoever drinks is not with him, except one who takes a handful, and most drank (Qur'an 2:249). The believers who crossed with him then said a small company can overcome a large one by Allah's permission. As the verse is worded, a handful was allowed, so the test was about measure and not thirst, and the crossing came after it.

The second river is Moses'. Allah tells his mother to put the baby in a chest and cast it into the river, and that the river will throw it on the bank (Qur'an 20:39), with the promise that He will return him to her (Qur'an 28:7). Here the river is the means of rescue. The third is Pharaoh's: "does not the kingdom of Egypt belong to me, and these rivers flowing beneath me" (Qur'an 43:51). Here the rivers are what a man points to as proof of his own greatness.