Deuteronomy 8:10 (ESV) … “And you shall eat and be full, and you shall bless the Lord your God for the good land he has given you.”
Moses then spelled out the danger inherent in abundant prosperity. Whereas in the wilderness they had to depend on God for the necessities of life, their newfound prosperity might conceal their need for the same dependence. Moses prescribed a sure antidote for this danger: praise the Lord your God. In fact failure to praise Him for His blessings was a step toward forgetting God and then disobeying His commands.
An Israelite who ceased to praise the Lord sincerely would find that his heart had become proud (v. 14) in his abundance (vv. 12–13; cf. Hosea 13:6). He would forget (cf. Deut. 8:11, 19; see comments on 4:9) the miraculous deliverance of Israel from Egypt … the land of slavery (cf. 5:6; 6:12; 7:8; 13:5, 10; Ex. 13:3, 14; 20:2) and the wilderness (cf. Deut. 1:19; 32:10) with its venemous snakes (cf. Num. 21:6–7) and scorpions. (This is the only reference in the Pentateuch to scorpions in the wilderness wanderings.) Such a person who did not remember God’s provisions of water (Ex. 15:25, 27; 17:5–7) and manna (Ex. 16) in the desert would be inclined to credit his own ability (my power and strength) for his wealth, when in reality it was as much a gift from God as the water out of hard rock had been in the wilderness. The provision of manna was a test, to see if Israel would depend on the Lord’s word (cf. comments on Ex. 16:4). Such dependence is humbling (cf. Deut. 8:3). The people could avoid pride in their wealth and strength if they would constantly remember the Lord and the lesson of the wilderness: all of life is a gift from God and nothing is possible apart from Him (v. 18).
Just as failure to praise God would lead to forgetting Him, so forgetting Him would lead to worshiping other gods. That in turn would result in certain destruction (death). If Moses’ audience wanted an example of national destruction all they needed to do was to remember the nations the Lord destroyed, namely, the kingdoms of Sihon and Og (2:26–3:11).