وَعَنْ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا
قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«إِذَا أَكَلَ أَحَدُكُمْ طَعَامًا، فَلَا يَمْسَحْ يَدَهُ، حَتَّى يَلْعَقَهَا، أَوْ يُلْعِقَهَا»
“When one of you eats, he must not wipe his hand till he licks it, or gives it to someone else to lick (such as a wife, husband, etc.).” Agreed upon.
Bulugh al-Maram 1640, Book 16, The Comprehensive Book, Hadith 6. 1 min read