Sunan Abi Dawud 33
سنن أبي داود#33Sahihحَدَّثَنَا أَبُو تَوْبَةَ الرَّبِيعُ بْنُ نَافِعٍ، حَدَّثَنِي عِيسَى بْنُ يُونُسَ، عَنِ ابْنِ أَبِي عَرُوبَةَ، عَنْ أَبِي مَعْشَرٍ، عَنْ إِبْرَاهِيمَ، عَنْ عَائِشَةَ، قَالَتْ كَانَتْ يَدُ رَسُولِ اللَّهِ صلى الله عليه وسلم الْيُمْنَى لِطُهُورِهِ وَطَعَامِهِ وَكَانَتْ يَدُهُ الْيُسْرَى لِخَلاَئِهِ وَمَا كَانَ مِنْ أَذًى .
Narrated Aisha, Ummul Mu'minin: The Prophet (ﷺ) used his right hand for getting water for ablution and taking food, and his left hand for his evacuation and for anything repugnant
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 1:33