Deuteronomy 31:28

28 Gather ye to me all the greater men in birth, and teachers [and doctors], by your lineages, and I shall speak to them, hearing these words, and I shall call (to witness) against them heaven and earth. (Gather ye to me all the men of great age, that is, the elders, of your tribes, and the officers, and I shall speak to them, and they shall hear all these words, and I shall call heaven and earth to witness against them.)

Deuteronomy 31:28 Meaning and Commentary

Deuteronomy 31:28

Gather unto me all the elders of your tribes, and your
officers
The heads of the tribes, the princes, and all other inferior magistrates:

that I may speak these words in their ears;
not the words of the law, but of the song which he was ordered to write, and is recorded in the following chapter:

and call heaven and earth to record against them;
to bear witness of what he delivered to them, and to bear witness against them should they transgress the laws he gave them; and to bear witness that they had been faithfully cautioned against transgressing, and had been severely threatened, and the punishment plainly pointed out that should be inflicted on them in case of disobedience, so that they were left entirely without excuse.

Deuteronomy 31:28 In-Context

26 Take ye this book (of the law), and put ye it in the side of the ark of the bond of peace of your Lord God, that it be there against thee into witnessing. (Take ye this Book of the Law, and put ye it beside the Ark of the Covenant of the Lord your God, to be a witness there against thee.)

27 For I know thy striving, and thy most hard noll; yet while I lived and entered with you, ye did ever[more] strivingly against the Lord; how much more when I shall be dead. (For I know thy defiance, or thy rebellious nature, and thy stiff neck/and thy stubbornness; yet while I lived and went with you, ye often defied the Lord; so then how much more, after that I am dead?)

28 Gather ye to me all the greater men in birth, and teachers [and doctors], by your lineages, and I shall speak to them, hearing these words, and I shall call (to witness) against them heaven and earth. (Gather ye to me all the men of great age, that is, the elders, of your tribes, and the officers, and I shall speak to them, and they shall hear all these words, and I shall call heaven and earth to witness against them.)

29 For I know, that after my death, ye shall do wickedly, and shall bow away soon from the way which I commanded to you; and evils shall come to you in the last time(s), when ye have done evil in the sight of the Lord, that ye stir him to wrath by the works of your hands. (For I know, that after my death, ye shall do wickedly, and shall soon turn away from the way which I commanded to you; and evils shall come to you in the days to come, when ye have done evil in the sight of the Lord, and so stir him to anger with the works of your hands.)

30 Therefore while all the company of the sons of Israel heard, Moses spake the words of this song, and he fulfilled it unto the end. (And so while all the congregation of the Israelites listened, Moses spoke the words of this song, and he spoke every word of it, from the beginning unto the end.)