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.'" (IT)
English reference (IT): Vol. 4, Book 29, Hadith 3270 (IT)
Arabic reference (IT): Book 29, Hadith 3395 (IT)