“So Manoah took a kid with a meat offering, and offered it upon a rock unto the LORD: and the Angel did wondrously; and Manoah and his wife looked on. 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. 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. And Manoah said unto his wife, We shall surely die, because we have seen God. But his wife said unto him, If the LORD were pleased to kill us, He would not have received a burnt offering and a meat offering at our hands, neither would He have shewed us all these things, nor would as at this time have told us such things as these.” Judges 13:19-23 (KJV)
Manoah had been prepared to offer a sacrifice unto a mere human messenger; but in verses 15-16 the LORD corrects Manoah, and directs him to offer the sacrifice unto Jehovah. When he does the offering is accepted.
This is a Theophany, a pre-incarnate appearance of Christ appearing as the Angel of the LORD.
This appearance is to tell Manoah and his wife of the coming conception and birth of their son Samson. He was to be dedicated to the LORD; refraining from the fruit of the vine, wines, and from any unclean foods, and his hair was to grow long. Samson was to be a Nazarite under a vow to the LORD.
Up to this point of their encounter with the Angel of the LORD they had only viewed him as a “Man of God”, when they offered to make an offering the Angel of the LORD says to them, “You must offer it to the LORD” (13:16). Where we are told in these verses that the “Angel of the LORD did wondrously” it would seem that that would mean He received the offering; approving it by fire. Then ascending up in the flame Himself. Thus Manoah’s and his wife’s falling on their faces to the ground in an act of worship
Manoah fears death after the LORD’S acceptance of their offering; yet his wife assures him that should not be the case. Manoah’s fear shows that he saw this Angel of the LORD as an appearance of God.
The Lord has appeared to mankind in the person of His Son Jesus to die for our sins, be buried, and rise bodily from the grave; putting away our sins for all eternity. Truly the LORD has done Wondrously.