2 Peter 2:16

But was rebuked for his iniquity
Which was not merely going along with the messengers of Balak, for he had leave from the Lord so to do, ( Numbers 22:20 ) ; but going along with them with a desire to curse Israel, when it was the will of God he should go and bless them, in order to get Balak's money; so that his governing iniquity was covetousness, which led him to other sins; and for this he was rebuked by the angel, ( Numbers 22:32 ) , as well as reproved by his ass, ( Numbers 22:28 ) : for

the dumb ass,
as it was naturally so, the ass on which he rode,

speaking with man's voice;
which was supernatural and miraculous, for it was God that opened the mouth of the ass: the mouth of that ass is said, by the Jews ^F13, to be one of the ten things created between the two evenings on the sixth day of the creation; that is, as the gloss on it says, concerning which it was decreed, that its mouth should be opened to speak what this ass said; and the occasion of it may be seen in ( Numbers 22:22-30 ) . Lactantius ^F14 observes, that there are two stars in the constellation of Cancer, which the Greeks call the "asses"; and which, the poets feign, are those that carried Liberus over a river, when he could not pass it; to one of which he gave this for a reward, "ut humana voce loqueretur", "that it should speak with man's voice"; a fable, no doubt, hatched from the sacred history, and said in imitation of this ass. Which

forbad the madness of the prophet:
and so Balaam, though a diviner and soothsayer, is called by the Jewish writers ^F15; who, they say, was first a prophet, and then a soothsayer, from whom Jerom ^F16 seems to have received the tradition; who says, that he was first a holy man, and a prophet of God, and afterwards, through disobedience, and a desire of gifts, was called a diviner; for his eyes were opened, and he saw the vision of the Almighty; and the Spirit of God came upon him, and he prophesied many things concerning Israel, and the Messiah, and others, ( Numbers 24:4-9 Numbers 24:16-24 ) . His madness lay in going with the messengers of Balak, ( Numbers 22:21 ) , in order to curse Israel, contrary to the will of God, ( Numbers 22:12 ) ; and it is madness in any to oppose God in his counsels, purposes, providences, and precepts; and every sin, which is an act of hostility against God, has madness in it; and this of Balaam's was forbid by his ass, and he was convinced of it. Very appropriately is mention made of this dumb ass, when the persons here spoken of were as natural brute beasts, and worse than them, ( 2 Peter 2:12 ) .