It wasnarrated from Jabir that the Messenger of Allah (ﷺ) said:
"Noneof you should wipe his hand until he has licked it, for he doesnotknow where the blessing if in his food.'" (JA)
English reference (JA): Vol. 4, Book 29, Hadith 3270 (JA)
Arabic reference (JA): Book 29, Hadith 3395 (JA)