John Calvin Commentary Deuteronomy 29:7

"And when ye came unto this place, Sihon the king of Heshbon, and Og the king of Bashan, came out against us unto battle, and we smote them:" — Deuteronomy 29:7 (ASV)

And when you came to this place. This is a third instance of God’s goodness: He had defeated the first enemies who encountered them to hinder their passage, and thus had already begun to bring them into a place of rest. For since the two and a half tribes had chosen their home here, they could see as in a mirror that the possession of the promised land awaited them.

Therefore, Moses concludes that they were under obligation to keep the law, and exhorts them to show their gratitude by faithful and sincere obedience. The object, therefore, of this account is to secure reverent attention to his doctrine, since the word שכל,²⁶¹ shakal, in Hiphil, means to act successfully as well as prudently. I have provided both readings, since they are equally suitable to the sense.

For we have seen in chapter 4 that this was the people’s only wisdom: to obey God’s statutes. Nor was their prosperity to be expected from any other source except God’s blessing, which is everywhere promised to the Israelites if they keep the law.

²⁶¹ תשכילו; A. V., that ye may prosper. S.M., ut prudenter agatis; but he adds, the Hebrews, explain this word by הצליחו, “that ye may prosper.” The Hiphil of שכל, says Simon’s Lexicon, is to act prudently, and by a metonymy of the antecedent for the consequent, to proceed prosperously. — W.