Sahih al-Bukhari 3321
Narrated Abu Huraira:
Allah's Messenger (ﷺ) 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."
حَدَّثَنَا الْحَسَنُ بْنُ الصَّبَّاحِ، حَدَّثَنَا إِسْحَاقُ الأَزْرَقُ، حَدَّثَنَا عَوْفٌ، عَنِ الْحَسَنِ، وَابْنِ، سِيرِينَ عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ غُفِرَ لاِمْرَأَةٍ مُومِسَةٍ مَرَّتْ بِكَلْبٍ عَلَى رَأْسِ رَكِيٍّ يَلْهَثُ، قَالَ كَادَ يَقْتُلُهُ الْعَطَشُ، فَنَزَعَتْ خُفَّهَا، فَأَوْثَقَتْهُ بِخِمَارِهَا، فَنَزَعَتْ لَهُ مِنَ الْمَاءِ، فَغُفِرَ لَهَا بِذَلِكَ ‏"‏‏.‏