Moses
Genesis 4:15ESV·traditional attribution

Then the LORD said to him, “Not so! If anyone kills Cain, vengeance shall be taken on him sevenfold.” And the LORD put a mark on Cain, lest any who found him should attack him.

John Calvin Reformed @genevareformer

15. Therefore , whosoever slayeth Cain . They who think that it was Cain’s wish to perish immediately by one death, in order that he might not be agitated by continual dangers, and that the prolongation of his life was granted him only as a punishment, have no reason, that I can see, for thus speaking.

Matthew Henry Presbyterian @wholebiblehenry

We have here a further account of the proceedings against Cain. I. Here is Cain's complaint of the sentence passed upon him, as hard and severe. Some make him to speak the language of despair, and read it, My iniquity is greater than that it may be forgiven; and so what he says is a reproach and affront to the mercy of God, which those...

Commenting on Genesis 4:13-15

John Gill Reformed Baptist @doctorgill

And Cain went out from the presence of the Lord,.... Either from the place where the Lord was talking with him; or from the place where his glorious Majesty usually resided, where was some visible token of his presence, some stream of light and glory which showed him to be there, and which was at the east of the garden of Eden; from whence Cain...