Ibn 'Abbas (May Allah be pleased with them) reported:
Messenger of Allah (ﷺ) said, "When one of you finishes eating, he should not wipe his fingers until he has licked them himself or has given them to someone else to lick for him."[Al-Bukhari and Muslim]. (DE)
App reference (DE): Book 3, Hadith 21 (DE)
Arabic/English book reference (DE): Book 3, Hadith 748 (DE)