Albert Barnes Commentary Psalms 110:2

"Jehovah will send forth the rod of thy strength out of Zion: Rule thou in the midst of thine enemies." — Psalms 110:2 (ASV)

The Lord shall send the rod of thy strength out of Zion — The scepter of your power; that with which you shall rule. It will be given to you by Yahweh; and it will be given to you, as it were, “out of Zion;” that is, as proceeding from the church, and as derived from that.

This appointment will be connected with the church, and it will be “as if” the church had conferred it on you. The idea is that the Messiah would receive, as it were, his designation, authority, commission, power from the church. He would spring from it (Isaiah 11:1); he would act for it; he would do what was needful for its good; he would wield the power which properly belongs to the church on the earth. .

Rule thou in the midst of thine enemies — Set up your power over them, and reign in them. This is a commission to set up a kingdom “in the very midst” of those who were his enemies; in the hearts of those who had been and were rebellious. His kingdom is set up not by destroying them, but by “subduing” them so that they become his willing servants.

They yield to him, and he rules over them. It is not here a commission to cut them off, but one much more difficult to execute—to make them his friends and to dispose them to submit to his authority. Mere “power” may crush people; it requires more than that to make rebels willingly submissive and to dispose them voluntarily to obey.