Sunan Abi Dawud, Hadith 3838 ⓘ
Ibn ‘Abbas reported the Messenger of Allah as saying : When one of you eats, he must not wipe his hand with a handkerchief till he licks it or gives it to someone to lick.
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنِ ابْنِ جُرَيْجٍ، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا أَكَلَ أَحَدُكُمْ فَلاَ يَمْسَحَنَّ يَدَهُ بِالْمِنْدِيلِ حَتَّى يَلْعَقَهَا أَوْ يُلْعِقَهَا " .
also referenced under: Hadith 3847 (DarusSalam)