Sunan Ibn Majah, Hadith 3267 ⓘ
It was narrated from Wahb bin Kaisan that he heard ‘Umar bin Abu Salamah say: “I was a boy in the care of the Prophet and my hand used to wander all over the plate. He said to me: ‘O boy! Say the Name of Allah, eat with your right hand, and eat from what is in front of you.’”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَمُحَمَّدُ بْنُ الصَّبَّاحِ، قَالاَ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الْوَلِيدِ بْنِ كَثِيرٍ، عَنْ وَهْبِ بْنِ كَيْسَانَ، سَمِعَهُ مِنْ، عُمَرَ بْنِ أَبِي سَلَمَةَ قَالَ كُنْتُ غُلاَمًا فِي حِجْرِ النَّبِيِّ ـ صلى الله عليه وسلم ـ وَكَانَتْ يَدِي تَطِيشُ فِي الصَّحْفَةِ فَقَالَ لِي " يَا غُلاَمُ سَمِّ اللَّهَ وَكُلْ بِيَمِينِكَ وَكُلْ مِمَّا يَلِيكَ " .
also referenced under: Book 29, Hadith 3391 (In-Book) & Volume 4, Book 29, Hadith 3267 (DarusSalam)