Judges 13:21 KJV
But the angel of the Lord did no more appear to Manoah and to his wife. Then Manoah knew that he was an angel of the Lord.
Judges 13:21, King James Version
In context
20 For it came to pass, when the flame went up toward heaven from off the altar, that the angel of the Lord ascended in the flame of the altar. And Manoah and his wife looked on it, and fell on their faces to the ground.
21 But the angel of the Lord did no more appear to Manoah and to his wife. Then Manoah knew that he was an angel of the Lord.
22 And Manoah said unto his wife, We shall surely die, because we have seen God.