Once a companion of the Prophet (S.A.W.W.) called Saad had gone to the battle field outside Medina. On the way, Saad heard that his mother who had been sick had died. Saad who loved his mother very much came to the Prophet (s.a.w.w.) and said that he had wanted to give charity on his mother's behalf but it had not been possible for him.

He then enquired if he could give charity on her behalf now that she was dead. The Prophet (s.a.w.w.) replied in the affirmative. Saad then went on to inquire what was the best charity he could offer? The Prophet (s.a.w.w.) said that on the route to the battle field he had seen that the soldiers were thirsty and there was a dire need of water.

The Prophet suggested that the best charity was to dig a well on the road so that caravans would benefit from the supply of water and it would also be a continuous form of charity for years to come. That was what Saad did. (AL MA'AAD BAINAL ROOH WAL JASAD, MUHAMMED TAQI FALSAFI VOL 2 PAGE 219)