Mukhtasar Muslim

Narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: A man was walking on the road in a state of great thirst when he found a well. He went down into it and drank water. Then he came out and saw a dog that, due to thirst, was sticking out its tongue, panting, and licking wet soil. The man said, "This dog's condition from thirst is just like mine was." Then he went down into the well, filled his sock with water, held the sock in his mouth, climbed up, and gave the water to the dog to drink. So Allah Almighty accepted this good deed of his and forgave him. The people asked, "O Messenger of Allah! Is there a reward for us in feeding and giving water to animals as well?" He (peace and blessings be upon him) said, "There is a reward in (doing good to) every living being with a moist liver." (He said this because the body and liver of a dead animal become dry.)