To put down the rebellion in Medina, Yezid sent a strong army under the one-eyed general called Muslim Bin Aqaba. Muslim brought back Medina under the control of Yezid but before he could do the same to Mecca, he died.
Hasin Bin Namir took-over from Muslim and went to Mecca, to deal with Abdullah Ibne Zubair whohad taken control of Mecca from Yezid. Before Hasin could win back Mecca, he got the news that Yezid had died.
Hasin hurried back to Damascus with whatever that he was left without food was left of his army. On the way and water. He and his army were about to die in the desert out of thirst and hunger. Then he saw a man coming in his direction. The man had a camel loaded with food and water. Hasin begged the man to sell to him the food and water, which he had with him for any price. The man replied that his provisions were not for sale. However, as Hasin needed them so badly he could have it all for free!
In his conversation with the stranger, Hasin recognized the stranger as being no other person than Ali Bin Husain (A.S). Thinking that the Imam had not recognised him, Hasin asked the Imam if he knew to whom the Imam was extending his generosity.
The Imam replied, “I know that you are the murderer of my brother and father and that you denied my father water and food till his martyrdom but that shows who you are and my generosity shows what I am”.
Hasin offered to help the Imam take control of Damascus. The Imam refused saying, all that he did for him was because he was a human being needing help. The Imam needed no reward or thanks. Saying so he went away - leaving behind Hasin to bite his figures in disbelief such was the generosity of our fourth Imam, Ali Bin Husain, Zainul Abidin (A.S).
Source:
A Brief Biography of Ali Ibn Husain (a.s)
By: Muhammad Reza Dungersi. PH.D
[Vol. 1, Pg. 26-27].