When they came into the wilderness of Arabah Moses addresses the descendants of the rebels.Most of the things he makes reference to were actually seen and experienced by the rebels rather than their sons.
DEUTERONOMY 11:1-7 NASB
11 “You shall therefore love the Lord your God, and always keep His charge, His statutes, His ordinances, and His commandments. 2 Know this day that I am not speaking with your sons who have not known and who have not seen the [a]discipline of the Lord your God—His greatness, His mighty hand and His outstretched arm, 3 and His signs and His works which He did in the midst of Egypt to Pharaoh the king of Egypt and to all his land; 4 and what He did to Egypt’s army, to its horses and its chariots, when He made the water of the [b]Red Sea to [c]engulf them while they were pursuing you, and the Lord [d]completely destroyed them; 7 but your own eyes have seen all the great work of the Lord which He did.
Most of those that had seen the hand of Lord from Egypt through the wilderness had actually died within the forty years after having refused to enter the promised land.But now Moses was addressing the sons of rebels rather the actually rebels themselves who had perished in the wilderness.
Deuteronomy 1 NASB
1 These are the words which Moses spoke to all Israel across the Jordan in the wilderness, in the Arabah opposite [a]Suph, between Paran and Tophel and Laban and Hazeroth and Dizahab. 2 It is eleven days’ journey from Horeb by the way of Mount Seir to Kadesh-barnea. 3 In the fortieth year, on the first day of the eleventh month, Moses spoke to the children of Israel, according to all that the Lord had commanded him to give to them,
Its clear that it was after the fortieth year after all the rebels had died that Moses made this address to the sons of the rebels.So why does Moses say it was the fathers rather than the sons whom he was addressing at Moab?