Alternative sources for this sermon
(see Bibliography for details of these texts)
When Amir al-mu'minin showed his intention to fight the Kharijites he was told that they had crossed the bridge of Nahrawan and gone over to the other side. Amir al-mu'minin said:Their falling place is on this side of the river. By Allah, not even ten of them will survive while from your side not even ten will be killed. 
As-Sayyid ar-Radi says: In this sermon "nutfah" implies the River Euphrates, and for water this is the nicest expression, even though water may be much.
Footnotes by translator:
This prophecy cannot be attributed to wit and farsightedness, because farsighted eyes may forecast victory or defeat and preconceive the outcome of war but to tell about the correct figures of the killed on either side is beyond their capacity. This can be done only by one who can unveil the unknown future and see the coming scene with his eyes and who sees the sketches yet to appear on the page of the future with the help of the light of knowledge possessed by him as Imam.
Consequently, events occurred just according to what this inheritor of the Prophet's knowledge had said, and from among the Kharijites all except nine persons were killed. Two of them fled away to `Uman, two to Sijistan, two to Kirman and two to al-Jazirah while one escaped to Tall Mawzan. Of Amir al-mu'minin's party only eight men fell as martyrs.