Deuteronomy 32:28

For they are a nation void of counsel, neither is there any understanding in them.

The verse belongs to the song God commanded Moses to frame out of His dealings with ancient Israel so the history of the past would not be forgotten, a song that recounts God's past dealings and foreshadows future events. It describes Israel as a nation void of wise counsel and spiritual understanding. That lack means failing to recognize the meaning and consequences of rebellion and being unable to consider where choices lead, the outcome of the course, and the latter end. This folly came because the people turned from God, forgot Him for other gods, worshiped false gods, and lacked faith.

Their lack of understanding stands in stark contrast to God's faithful care and the Lord's power, and is exposed by military weakness where one enemy can rout many because their Rock has delivered them into defeat. In context the verse warns that forgetting God brings rebellion and judgment and explains why the people persist in apostasy and face judgment, with calamity swiftly overtaking those who persist, including rebellion, scattering, and defeat. The song's warnings were fulfilled in the nation's captivity and the destruction of the Temple and its religious services, yet God did not allow enemies to utterly destroy Israel lest the enemy claim victory by its own power, and the song ultimately points to the final victory of the faithful when Christ returns in power and glory.

By contrast, obedience to God's law was their life and would prolong their days in the land; the warning applies to disregard for God's law and Sabbath, and parents' failure to teach children obedience contributes to the world's sinful condition. The song was to be learned, memorized, taught by parents to children, and repeated in worship and daily life, with memorials gathered and preserved in sight so that when children inquired the whole story of God's providential dealings, marked goodness and mercy in care and deliverance could be repeated. Remembering these waymarks keeps reason for joy, gladness, praise and thanksgiving to God as the Fountain of life and power who makes the wilderness a fruitful field for the people that keep His commandments, and that same recounting of God's goodness belongs before young and old in this generation as warning and reproof for the whole nation. In one setting the verse applies to the Northern army's leaders, who seek guidance from deceptive spirits instead of trusting God, and whose lack of discernment leaves them open to error and defeat.