Judges 13:20

‘ For so it was that when the flame went up towards heaven from off the altar, the Angel of Yahweh ascended in the flame of the altar, and Manoah and his wife looked on, and they fell on their faces to the ground.'

Notice the stress again on the dual witness. This incident was seen as so remarkable that such an emphasis was necessary. For as the fire burned, consuming the burnt offering, the Angel of Yahweh seemed to merge with the sacrificial flames and ascended upwards, disappearing from sight. He had returned to Yahweh to whom the offering was offered. Such was the mystery of it that both man and wife fell on their faces to the ground in awe and wonder.