Then the Lord opened the eyes of Balaam— i.e. He presented to his view the angel who had hitherto been invisible; or, as others interpret it, he awakened his attention, and made him take notice of the angel, whom he had not before observed. See Genesis 3:7; Genesis 21:19. Bishop Patrick understands it as the dissipation of a blindness which had surrounded him, and which he supposes to be similar to that with which the Sodomites were stricken; Genesis 19:11; see 2 Kings 6:17.
Related Commentaries of Numbers 22:31
Numbers 22:31
31 Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way, and his sword drawn in his hand: and he bowed down his head, and fell flat on his face.