Moses
Numbers 21:27BSB·traditional attribution

That is why the poets say: “Come to Heshbon, let it be rebuilt; let the city of Sihon be restored.

John Calvin Reformed @genevareformer

27. Wherefore, they that speak in proverbs. That is, an old saying, or proverbial sentence remains, and is well known. The song, however, appears to have been composed in the character of those who, when prepared to engage in war, mutually exhorted each other, “Come into Heshbon,” i.e., run to the standard of king Sihon; hasten to his home, and his chief place of abode...

Matthew Henry Presbyterian @wholebiblehenry

We have here an account of the victories obtained by Israel over Sihon and Og, which must be distinctly considered, not only because they are here distinctly related, but because long afterwards the memorial of them is distinctly celebrated, and they are severally assigned as instances of everlasting mercy.

Commenting on Numbers 21:21-35

John Gill Reformed Baptist @doctorgill

We have shot at them,.... Either the Amorites at the Moabites, or else the Israelites at the Amorites; for, according to Aben Ezra, these are the words of Moses, though they, with Num 21:29, seem rather to be a continuation of the song of the old Amorite bards, describing the ruin of the country of Moab by them; and this clause may be rendered with...