John Calvin Commentary Numbers 23:18

"And he took up his parable, and said, Rise up, Balak, and hear; Hearken unto me, thou son of Zippor:" — Numbers 23:18 (ASV)

And he took up his parable and said. We have already explained the meaning of this expression, namely, to use glowing and elevated language in order to awaken the hearer's attention more effectively. The same is also the object of the preface, Rise up, Balak, and hear; listen to me, you son of Zippor; for such repetitions are mostly emphatic and indicate something uncommon.

When he declares that God cannot lie, because he is not like men, it is a severe kind of censure, as if to say, “Would you make God a liar?” For it was necessary that Balak's frantic eagerness should be repressed and prevented from going any further. From this, however, a lesson of supreme usefulness can be drawn: namely, that men are altogether wrong when they form their estimate of God from their own disposition and habits. Still, almost all men labor under this mistake. For how is it that we are so prone to waver, if not because we weigh God’s promises on our own scale?

Therefore, so that we may learn to lift our minds above the world whenever the faithfulness and certainty of God’s word are in question, it is good for us to reflect on how great the distance is between ourselves and God. Men are accustomed to lie, because they are fickle and changeable in their plans, or because sometimes they are unable to accomplish what they have promised. But a change of purpose arises either from levity or bad faith, or because we repent of what we have spoken foolishly and inconsiderately.

But to God nothing of this sort occurs, for He is neither deceived, nor does He deceitfully promise anything; nor, as James says, is there with Him any shadow of turning (James 1:7). We now understand to what this dissimilarity between God and men refers: namely, that we should not distort God according to our own notions. Instead, in our consideration of His nature, we should remember that He is subject to no changes, since He is far above all heavens.

Regarding the meaning of the repentance of God, of which mention is often made, let my readers seek it elsewhere in its proper place. We must, however, at the same time, observe the application of the lesson. For the words God is true would have no effectiveness in themselves unless they are applied to their appropriate use; that is, that we should with unhesitating faith rely on His promises and seriously tremble at His threats.

For with the same aim it is said that the word of God is pure and perfect, and is compared with gold refined seven times in the fire. This also is the tendency of the conclusion, which is soon added: Shall He not fulfill what He has spoken? Balak desired to have the people cursed, whom God had adopted; Balaam declares that this is impossible, because God is unchangeable in what He has decreed.

In a word, he teaches us the same truth as Paul does: that the election of His people is without repentance, because it is founded on the gratuitous liberality of God (Romans 11:29). If, then, this saying was extorted from the hireling false prophet, how inexcusable will be our stupidity if our minds vary and waver in embracing God’s word, as if He Himself were variable.