Albert Barnes Commentary Hebrews 10:13

"henceforth expecting till his enemies be made the footstool of his feet." — Hebrews 10:13 (ASV)

From now on expecting. Or, waiting. He waits there until this is accomplished according to the promise made to him that all things will be subdued under him (1 Corinthians 15:25 and following).

Till his enemies. There is an allusion here to Psalm 110:1, where it is said, The Lord said unto my Lord, Sit thou at my right hand until I make thine enemies thy footstool. The enemies of the Redeemer are Satan, the wicked of the earth, and all the evil passions of the heart.

The idea is that all things are yet to be made subject to his will—either by a cheerful and cordial submission to his authority, or by being crushed beneath his power. The Redeemer, having performed his great work of redemption by giving himself as a sacrifice on the cross, is represented now as calmly waiting until this glorious triumph is achieved, and this promise is fulfilled. We are not to suppose that he is inactive, or that he takes no share in the agency by which this is to be done, but the meaning is that he looks to the certain fulfillment of the promise.

His footstool. That is, they will be thoroughly and completely subdued. The same idea is expressed in 1 Corinthians 15:25, by saying that all his enemies will be put under his feet. The language arose from the custom of conquerors in putting their feet on the necks of their enemies, as a symbol of subjection. See Joshua 10:24; Isaiah 26:5–6.