Moses
Deuteronomy 31:12BSB·traditional attribution

Assemble the people—men, women, children, and the foreigners within your gates—so that they may listen and learn to fear the LORD your God and to follow carefully all the words of this law.

John Calvin Reformed @genevareformer

12. Gather the people together. “Congregando,” by congregating — Lat. There is much abridgment of the passage in the French. Literally, “to gather,” הקהל. The form is strictly that of the imperative Hiphil, whilst the infinitive of the same voice is properly הקהיל, as seen in Numbers 10:7, though its yod might be changed into a tzere, in which case the form of these two different tenses would be identical.

Matthew Henry Presbyterian @wholebiblehenry

The law was given by Moses; so it is said, Joh 1:17. He was not only entrusted to deliver it to that generation, but to transmit it to the generations to come; and here it appears that he was faithful to that trust. I. Moses wrote this law, Deu 31:9.

Commenting on Deuteronomy 31:9-13

John Gill Reformed Baptist @doctorgill

And that their children, which have not known anything,.... Of God and of his law and of their duty to God, to their parents, and the rest of their fellow creatures: may hear, and learn to fear the Lord your God; hear the law of God, learn the meaning of it, and so be brought up in the fear, nurture, and admonition of the Lord...