Hazrat Abu al-Bakhtari narrates that he says: A man from the tribe of Banu Abs was with Hazrat Salman. He came to the river Dijlah (Tigris), so Hazrat Salman said to him, "Drink water." He drank water. Then he said to him, "Drink water." He drank water. Then he said to him, "Drink water." He drank water. Then Hazrat Salman (may Allah be pleased with him) said to him, "O brother of Banu Abs! Do you see that your sip has lessened the water of this Dijlah?" In the same way, knowledge is an unending thing. So seek beneficial knowledge for yourself. Then he passed by some canals where there was some food and grains were being blown away in the air. He said, "O brother of Banu Abs! That man who was the owner of its treasures while you were alive, those people would pass their mornings and evenings in such a state that they did not have even a qafeez of wheat among them." Then he mentioned Jalula and the conquests of the Muslims regarding it and said, "O brother of Banu Abs! Allah Almighty has granted you this, although Allah Almighty was capable of this even when Muhammad (peace be upon him) was alive."