Hadees

Allah's Apostle (sallallähu alaihi wasallam) said, "A prostitute was forgiven by Allah, because, passing by a panting dog near a well and seeing that the dog was about to die of thirst, she took off her shoe, and tying it with her head-cover she drew out some water for it. So, Allah forgave her because of that."

[Bukhari Book:54 No:538]