Narrated 'Abdullah bin Rafi':
"I said to Abu Hurairah: 'Why were you given the Kunyah Abu Hurairah?' He said: 'Do you not fear me?'" He said: "Indeed, I am in awe of you.' He said: 'I used to tend the sheep of my people, and I had a small kitten; so I used to place it in a tree at night, and during the day I would take it and play with it. So they named me Abu Hurairah.'"
حَدَّثَنَا أَحْمَدُ بْنُ سَعِيدٍ الْمُرَابِطِيُّ، حَدَّثَنَا رَوْحُ بْنُ عُبَادَةَ، حَدَّثَنَا أُسَامَةُ بْنُ زَيْدٍ، عَنْ عَبْدِ اللَّهِ بْنِ رَافِعٍ، قَالَ قُلْتُ لأَبِي هُرَيْرَةَ لِمَ كُنِّيتَ أَبَا هُرَيْرَةَ قَالَ أَمَا تَفْرَقُ مِنِّي قُلْتُ بَلَى وَاللَّهِ إِنِّي لأَهَابُكَ ‏.‏ قَالَ كُنْتُ أَرْعَى غَنَمَ أَهْلِي فَكَانَتْ لِي هُرَيْرَةٌ صَغِيرَةٌ فَكُنْتُ أَضَعُهَا بِاللَّيْلِ فِي شَجَرَةٍ فَإِذَا كَانَ النَّهَارُ ذَهَبْتُ بِهَا مَعِي فَلَعِبْتُ بِهَا فَكَنَّوْنِي أَبَا هُرَيْرَةَ ‏.‏ قَالَ هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ ‏.‏
GradeHasan (Darussalam)
English reference : Vol. 1, Book 46, Hadith 3840
Arabic reference : Book 49, Hadith 4211