John Calvin Reformed @genevareformer

5. And I have led you. He descends to the blessings with which He had continually visited His people during the course of forty years. Yet he does not recount them all, but contents himself with a few of the most remarkable instances, viz., that their clothes had not been worn out by age, and that they had been fed from heaven, when no sustenance...

Matthew Henry Presbyterian @wholebiblehenry

Now that Moses had largely repeated the commands which the people were to observe as their part of the covenant, and the promises and threatenings which God would make good (according as they behaved themselves) as part of the covenant, the whole is here summed up in a federal transaction.

Commenting on Deuteronomy 29:1-9

John Gill Reformed Baptist @doctorgill

And I have led you forty years in the wilderness,.... From the time of their coming out of Egypt unto that day, which though not quite complete, is given as a round number. Eupolemus (d), an Heathen writer, confirms this date of the ministry of Moses among the Israelites; he says, Moses performed the office of a prophet forty years: your clothes are not waxen...