John Calvin Commentary Deuteronomy 8:1

"All the commandment which I command thee this day shall ye observe to do, that ye may live, and multiply, and go in and possess the land which Jehovah sware unto your fathers." — Deuteronomy 8:1 (ASV)

All the commandments. Although the first verse might have been included among the promises by which, as we shall later see, the Law was ratified by Moses—because he here exhorts and urges the Israelites to obedience by proposing to them the hope of reward—I still thought it fitting to include it here. This is because Moses's simple design was to draw them by the sweetness of the promised inheritance to accept the doctrines of the Law.

This sentence, then, can be rightly counted among those by which their minds were prepared to submit to God with the gentleness and teachableness that was appropriate for them. It is as if he had said: Because the land of Canaan is now near you, its very nearness ought to encourage you to take God’s yoke upon yourselves more cheerfully. For the same God who declares His law to you this day invites you to the enjoyment of that land, which He promised with an oath to your fathers.

And certainly, it is evident from this later part of the verse that Moses did not simply promise them a reward if they should keep the Law. Rather, he set before them the prior favor with which God had, by His grace, acted first for them, so that they, on their part, might show themselves grateful for it.

Moses calls the commandments his, not (as we have already seen) because he had invented them himself, but because he faithfully handed them down as dictated from God’s own mouth.

We may also gather this more fully from the following verse, in which he recounts past mercies and, at the same time, reminds them of the many proofs by which God had instructed them, to shape and accustom them to obedience.

In the first place, he tells them to remember generally God's dealings, which they had seen for forty years. He then descends to particulars: namely, that God had tested them with afflictions, to know what was in their heart. For the expressions can be paraphrased this way: to humble thee, and to prove thee, to know what was in thine heart. In these words, he admonishes them that they were painfully tested by many troubles and difficulties for a very good reason—that is, because they needed such testing.

Yet, at the same time, he indirectly rebukes their stubbornness, which was then revealed. For if everything had gone prosperously for them, it would have been easy for them to feign great fear of God, even though, as was actually discovered, it did not truly exist.