John Calvin Commentary Deuteronomy 29:5

"And I have led you forty years in the wilderness: your clothes are not waxed old upon you, and thy shoe is not waxed old upon thy foot." — Deuteronomy 29:5 (ASV)

And I have led you. He then proceeds to the blessings with which He had continually favored His people during forty years. Yet he does not recount them all, but contents himself with a few of the most remarkable instances, namely, that their clothes had not been worn out by age, and that they had been fed from heaven when no sustenance could be obtained from the fruits of the earth. He reminds them that God’s glory had been manifested by these testimonies, so that they might submit themselves to His rule.