Moses
Deuteronomy 1:3BSB·traditional attribution

In the fortieth year, on the first day of the eleventh month, Moses proclaimed to the Israelites all that the LORD had commanded him concerning them.

Matthew Henry Presbyterian @wholebiblehenry

We have here, I. The date of this sermon which Moses preached to the people of Israel. A great auditory, no question, he had, as many as could crowd within hearing, and particularly all the elders and officers, the representatives of the people; and, probably, it was on the sabbath day that he delivered this to them. 1.

Commenting on Deuteronomy 1:1-8

John Gill Reformed Baptist @doctorgill

And it came to pass in the fortieth year,.... That is, of the coming of the children of Israel out of Egypt: in the eleventh month; the month Shebet, as the Targum of Jonathan, which answers to part of January and part of February: in the first day of the month, that Moses spoke unto the children of Israel according to all that the Lord...

Jamieson-Fausset-Brown Reformed @jfbcommentary

in the fortieth year . . . Moses spake unto the children of Israel, &c.--This impressive discourse, in which Moses reviewed all that God had done for His people, was delivered about a month before his death, and after peace and tranquillity had been restored by the complete conquest of Sihon and Og.