سنن أبي داود

Abu Hurairah reported the Messenger of Allah(ﷺ) as saying “ While a man was going on his way, he felt himself thirsty severely. He found a well and e went down in it. He drank water and came out. Suddenly he saw a dog panting and eating soil due to thirst. The man said (to himself) “This dog must have reached the same condition due to thirst as I had reached. So he went down into the well, filled his sock with water, held it with his mouth and came up. He supplied water to the dog. Allaah appreciated this and forgave him.” They asked “Apostle of Allaah(ﷺ), Is there any reward for us for these beasts? He replied, For every cool liver there is a reward.”