Hadith 20:2
Sahih (Al-Albani)
Mu'awiya ibn Qurra reported that his father said, "A man said, 'Messenger of Allah, I was going to slaughter a sheep and then I felt sorry for it (or 'sorry for the sheep I was going to slaughter').' He said twice, 'Since you showed mercy to the sheep, Allah will show mercy to you.'"
حَدَّثَنَا مُسَدَّدٌ، قَالَ: حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ، قَالَ: حَدَّثَنَا زِيَادُ بْنُ مِخْرَاقٍ، عَنْ مُعَاوِيَةَ بْنِ قُرَّةَ، عَنْ أَبِيهِ قَالَ: قَالَ رَجُلٌ: يَا رَسُولَ اللهِ، إِنِّي لَأَذْبَحُ الشَّاةَ فَأَرْحَمُهَا، أَوْ قَالَ: إِنِّي لَأَرْحَمُ الشَّاةَ أَنْ أَذْبَحَهَا، قَالَ: وَالشَّاةُ إِنْ رَحِمْتَهَا، رَحِمَكَ اللَّهُ مَرَّتَيْنِ
Original Reference: Al-Adab Al-Mufrad 373