And the ass saw the angel of the Lord. This was clearly part of the miracle, the σήμειον which was to exhibit in such a striking manner the stupidity and blindness of the most brilliant and gifted intellect when clouded by greed and selfishness.
It is nothing to the point that the lower animals have a quicker perception of some natural phenomena than men, for this was not a natural phenomenon; it is nothing to the point that the lower animals are credited by some with possessing "the second sight," for all that belongs to the fantastic and legendary.
If the ass saw the angel, it was because the Lord opened her eyes then, as he did her mouth afterwards.