(9) Only take heed to thyself.--The exhortation contained in the following verses lays special emphasis on one point--the worship of the invisible Jehovah without images. This more than anything else would tend to separate the religion of Israel from that of all other nations.

Teach them thy sons, and thy sons' sons.--A command which Israel evidently failed to obey. For a generation speedily rose up "which knew not Jehovah nor yet the works which he had done for Israel" (Judges 2:10). It is worth while to observe that we cannot find any trace of a system of national education in Israel until many years later. When education is purely parental, it is likely to be neglected in many instances. It is not every parent who finds himself able to "teach his sons, and his sons' sons."

Verses 9-14. - The possession of the oracles of God by Israel was a benefit to them only as these were kept in mind and reverently obeyed. Therefore they were to take heed and diligently beware of forgetting the circumstances under which the Law had been received at Horeb. God had then commanded the people to be gathered together, so that they stood before the Lord, were in his manifested presence, and were made to hear his voice speaking to them from amidst the fire and the clouds that covered the mount. They had thus actual evidence and guarantee that the Law they had received was Divine; and this they were to keep in mind as long as they lived, and to communicate to their children in all coming time, that so they might fear the Lord; for on this rested that covenant which God had made with Israel, and which they were to keep as the condition of their continuing to enjoy privilege and life. Verse 9. - Keep thy soul diligently; i.e. Be very careful to preserve thy life (cf. Job 2:6; Proverbs 13:3; Proverbs 16:17; Proverbs 19:16; in all which passages the same formula is used as here). The Hebrew (נֶפֻשׁ) means primarily breath, then vital principle, natural life (anima), then soul life, the soul or mind (animus). The forgetting of the wonders they had seen would lead to their forgetting God, and so to their departing from him, and this would mar and ultimately destroy their life (cf. Joshua 23:11-16). The things which thine eyes have seen (see Exodus 19:10, etc.).

4:1-23 The power and love of God to Israel are here made the ground and reason of a number of cautions and serious warnings; and although there is much reference to their national covenant, yet all may be applied to those who live under the gospel. What are laws made for but to be observed and obeyed? Our obedience as individuals cannot merit salvation; but it is the only evidence that we are partakers of the gift of God, which is eternal life through Jesus Christ, Considering how many temptations we are compassed with, and what corrupt desires we have in our bosoms, we have great need to keep our hearts with all diligence. Those cannot walk aright, who walk carelessly. Moses charges particularly to take heed of the sin of idolatry. He shows how weak the temptation would be to those who thought aright; for these pretended gods, the sun, moon, and stars, were only blessings which the Lord their God had imparted to all nations. It is absurd to worship them; shall we serve those that were made to serve us? Take heed lest ye forget the covenant of the Lord your God. We must take heed lest at any time we forget our religion. Care, caution, and watchfulness, are helps against a bad memory.Only take heed to thyself,.... To walk according to this law, and not swerve from it:

and keep thy soul diligently; from the transgressions and breaches of it:

lest thou forget the things which thine eyes have seen; either the statutes and judgments set before them, and the circumstances of the delivery of them; or the punishment inflicted on the breakers of them; or the favours bestowed on those that observed them:

and lest they depart from thy heart all the days of thy life; out of thy mind and memory, and have no place in thy affections, through a neglect and disuse of them:

but teach them thy sons, and thy sons' sons; their children and grandchildren, that they may be trained up in them in their youth, and so not depart from them when grown up, and in years; see Deuteronomy 6:7.