It was narrated from Ibn ‘Abbas that the Prophet ﷺ said:
“When one of you eats food, let him not wipe his hand until he has licked it or has someone else to lick it.”

حَدَّثَنَا مُحَمَّدُ بْنُ أَبِي عُمَرَ الْعَدَنِيُّ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ النَّبِيَّ ﷺ قَالَ " إِذَا أَكَلَ أَحَدُكُمْ طَعَامًا فَلاَ يَمْسَحْ يَدَهُ حَتَّى يَلْعَقَهَا أَوْ يُلْعِقَهَا " .