Mukhtasar Bukhari

Narrated from Sayyiduna Abu Huraira (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "A man was walking when he was overcome by thirst, so he went down into a well and drank water from it. Then he came out and saw a dog panting and licking wet earth due to severe thirst. The man said (to himself), 'This dog has suffered thirst just as I have.' So he went down into the well again, filled his sock with water, held it in his mouth, climbed up, and gave the dog water to drink. Allah accepted this deed of his and forgave him." The people asked, "O Messenger of Allah! Is there a reward for us in serving animals?" He (peace and blessings of Allah be upon him) said: "Yes! There is a reward in serving every living (moist-livered) creature."