John Gill Commentary Exodus 10:2

"and that thou mayest tell in the ears of thy son, and of thy son`s son, what things I have wrought upon Egypt, and my signs which I have done among them; that ye may know that I am Jehovah." — Exodus 10:2 (ASV)

And that you may tell in the ears of your son, and of your
son's son
Not of his sons and grandsons only; for Moses here, as Aben Ezra observes, was in the stead of Israel; and the sense is, that it should be told to their posterity in all succeeding ages:

what things I have wrought in Egypt ;
the plagues that he inflicted on the Egyptians:

and my signs which I have done amongst them ;
meaning the same things which were signs:

that you may know how that I am the Lord ;
that their God is the true Jehovah, and the one only living and true God; the Lord God omnipotent, omniscient, omnipresent, infinite, and eternal.