Num 23:19 God is not a man, that he might lie, or a son of man, that he might change his mind. Does he speak and not act, or promise and not fulfill?
The oracle consists of an introductory statement in which Balak was told directly that the immutable God of Israel had promised to bless His people Israel and would not change His mind. Balaam, moreover, had just been given a command to bless and in the face of God’s unbreakable commitment to Israel, Balaam had no power to do otherwise.