John Calvin Commentary Deuteronomy 31:20

"For when I shall have brought them into the land which I sware unto their fathers, flowing with milk and honey, and they shall have eaten and filled themselves, and waxed fat; then will they turn unto other gods, and serve them, and despise me, and break my covenant." — Deuteronomy 31:20 (ASV)

But when I have brought them. In other words, God again emphasizes the atrociousness of their iniquity: in that when He had treated the Israelites generously, they would turn His benefits into occasions of perversity. Indeed, nothing can be more base than such ingratitude.

He then says that He will perform for them, unworthy as they are, what He has sworn, so that He might thus be faithful to His promises. He commends the fertility of the land, since this striking pledge of His indulgence should have attracted them by its sweetness to love so beneficent a Father in return.

Therefore, the perverseness of their nature is demonstrated, since, when full, they would kick against Him, like horses that become intractable from rich feeding. But, after complaining of their future rebellion, He again says that when they have been brought into dire straits and overwhelmed with miseries, this song would be “as a witness,” as if they should proclaim in it their own condemnation.

When He says that He knew their disposition,²⁴⁴ or what they formed within themselves (for the word employed is יצר, yetzer, which is equivalent to figment, or imagination, and includes all the thoughts and feelings), it is apparent that He was by no means unaware that He was bestowing His benefits upon such unworthy persons. Instead, He thus contended with their unworthiness, so that His goodness might be more conspicuous.

He also desired this instruction to be set before them, ungodly and hopeless as they were—instruction He knew they would despise—thereby rendering them all the more inexcusable by this test.

But it may be objected: Why then did He not turn their hearts to better things? For this is how ungodly scoffers allow themselves to dispute with Him. But let us rather reflect on the words of Paul: Nay but, O man, who art thou that repliest against God? Hath not the potter power over the clay, to make of it vessels according to his own will? (Romans 9:20, 21). And,

Who hath first given to him, and it shall be recompensed unto him again? (Romans 11:35).

So it will come to pass that we will exclaim with trembling: Oh, how deep are the judgments of God; how incomprehensible are His ways!

That God should judge from their former life what they would be in the future does not seem very logical. But these two points are to be taken together: first, God foresees that nothing else is to be expected from them but that they would be carried away into sin by their unbridled lust; and secondly, it had already been sufficiently manifested by their many iniquities how desperate their obstinacy was.

²⁴⁴ A. V., “Their imagination.” “The thing forged in their heart.” — Ainsworth. “Figmentum;” Taylor, from ., “Their imagination.” “The thing forged in their heart.” — Ainsworth. “Figmentum;” Taylor, from יצר, , fingere, , formare