Deuteronomy 4:3

4:3 You have witnessed what the Lord did at Baal Peor, how he eradicated from your midst everyone who followed Baal Peor.

Deuteronomy 4:9

Reminder of the Horeb Covenant

4:9 Again, however, pay very careful attention, lest you forget the things you have seen and disregard them for the rest of your life; instead teach them to your children and grandchildren.