Al-Adab Al-Mufrad, Hadith 174 ⓘ
Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "When one of you strikes his servant, let him avoid his face."
حَدَّثَنَا خَالِدُ بْنُ مَخْلَدٍ، قَالَ: حَدَّثَنَا سُلَيْمَانُ بْنُ بِلاَلٍ قَالَ: حَدَّثَنِي مُحَمَّدُ بْنُ عَجْلاَنَ قَالَ: أَخْبَرَنِي أَبِي، وَسَعِيدٌ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: إِذَا ضَرَبَ أَحَدُكُمْ خَادِمَهُ فَلْيَجْتَنِبِ الْوَجْهَ.
also referenced under: Book 9, Hadith 19 (In-Book) & Book 9, Hadith 174 (English)