John Calvin on Deuteronomy 29:2-3

2. And Moses called unto all Israel. This passage also may be fitly referred to the preface of the Law, since its tendency is to recommend it, and to instruct and prepare the people’s minds to be teachable. It takes its commencement from the divine blessings, which they had experienced as well in their exodus as in their forty years’ wanderings; for it would have been the height of baseness and ingratitude not to devote themselves to a Deliverer who had dealt so graciously with them. And surely it was an inestimable sign of His paternal love towards them, that He should have arrayed Himself against so very powerful a king for His servants’ sake. Finally, lest there should be any question as to their deliverance, he enlarges upon the power which God displayed therein, in magnificent terms of praise according with its dignity.