Please read the text before the commentary.
Moses has the people reflect on their past relations with the LORD. With the Lord’s mighty arm and great goodness, God took to himself the children of Israel. Moses’ people had seen all this, and experienced all this, There was only one thing remaining. Because of all they had seen: the children of Israel had to keep God’s commandments and statutes, and they would have long life with the Lord.
Now, when we feel the heat of summer, or the depression of our lives, or an unexplained weariness in our bones, it is time for us to remember the many mighty deeds of the Lord and praise and thank the Lord for isi greatness. The result is sharing long life on the land that the Lord God gives us forever.
The book of Deuteronomy is set with the people about to enter the Promised Land. The author sets it as the Israelites are about to enter the land forty years after having left Egypt. It just as easily can be set at the people are about to return after the exile in Babylon.
It matters not in the long run. What matters is learning how to see the August presence of God in our lives so that we can remember the testings and the great signs and wonders the Lord has done on our behalf. We have heard him speak, we have experienced his fire, his wind, the powers of nature and the beauty of creation. Therefore, we must keep his statutes and commandments so that we can have long life with the Lord forever.