A full stop should end Deuteronomy 4:9; and Deuteronomy 4:10 begin, At the time that thou stoodest, etc. Deuteronomy 4:11 then ye came near, etc. Moses, exhorting to heedful observance of the Law, strives to renew the impressions of that tremendous scene which attended its promulgation at Sinai.

Only take heed to thyself - Be circumspect and watchful.

Keep thy soul diligently - Be mindful of thy eternal interests. Whatever becomes of the body, take care of the soul.

Lest thou forget - God does his work that they may be had in everlasting remembrance; and he that forgets them, forgets his own mercies. Besides, if a man forget the work of God on his soul, he loses that work.

Lest they depart from thy heart - It is not sufficient to lay up Divine things in the memory, they must be laid up in the heart. Thy word have I hidden in my heart, says David, that I might not sin against thee. The life of God in the soul of man can alone preserve the soul to life everlasting; and this grace must be retained all the days of our life. When Adam fell, his condition was not meliorated by the reflection that he had been once in paradise; nor does it avail Satan now that he was once an angel of light. Those who let the grace of God depart from their hearts, lose that grace; and those who lose the grace, fall from the grace; and as some have fallen and risen no more, so may others; therefore, take heed to thyself, etc. Were it impossible for men finally to fall from the grace of God, exhortations of this kind had never been given, because they would have been unnecessary, and God never does an unnecessary thing.

But teach them thy sons - If a man know the worth of his own soul, he will feel the importance of the salvation of the souls of his family. Those who neglect family religion, neglect personal religion; if more attention were paid to the former, even among those called religious people, we should soon have a better state of civil society. On family religion God lays much stress; and no head of a family can neglect it without endangering the final salvation of his own soul. See the note at the conclusion of Genesis 18:32 (note), Genesis 19:38 (note), and Deuteronomy 6:7 (note).

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.

Israel was therefore not to forget the things which it had seen at Horeb with its own eyes.

Deuteronomy 4:9

"Only beware and take care of thyself." To "keep the soul," i.e., to take care of the soul as the seat of life, to defend one's life from danger and injury (Proverbs 13:3; Proverbs 19:16). "That thou do not forget את־הדּברים (the facts described in Exodus 19-24), and that they do not depart from thy heart all the days of thy life," i.e., are not forgotten as long as thou livest, "and thou makest them known to thy children and thy children's children." These acts of God formed the foundation of the true religion, the real basis of the covenant legislation, and the firm guarantee of the objective truth and divinity of all the laws and ordinances which Moses gave to the people. And it was this which constituted the essential distinction between the religion of the Old Testament and all heathen religions, whose founders, it is true, professed to derive their doctrines and statutes from divine inspiration, but without giving any practical guarantee that their origin was truly divine.

Only take heed to thyself, and {h} keep thy soul diligently, lest thou forget the things which thine eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them thy sons, and thy sons' sons;

(h) He adds all these words, to show that we can never be careful enough to keep the law of God and to teach it to our posterity.

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.