Moses
Genesis 36:31ESV·traditional attribution

These are the kings who reigned in the land of Edom, before any king reigned over the Israelites.

John Calvin Reformed @genevareformer

31. These are the kings that reigned, etc We must keep in memory what we have said a little before, that reprobates are suddenly exalted, that they may immediately fall, like the herb upon the roofs, which is destitute of root, and has a hasty growth, but withers the more quickly. To the two sons of Isaac had been promised the honor that kings should spring from them.

Matthew Henry Presbyterian @wholebiblehenry

By degrees, it seems, the Edomites wormed out the Horites, obtained full possession of the country, and had a government of their own. 1. They were ruled by kings, who governed the whole country, and seem to have come to the throne by election, and not by lineal descent; so bishop Patrick observes.

Commenting on Genesis 36:31-43

John Gill Reformed Baptist @doctorgill

And Hadad died,.... As is supposed, about A. M. 2241. and Samlah of Masrekah reigned in his stead; but who he was, or the place he was of, cannot be said.