By the which will - That is, by his obeying God in the manner specified. It is in virtue of his obedience that we are sanctified. The apostle immediately specifies what he means, and furnishes the key to his whole argument, when he says that it was “through the offering of the body of Jesus Christ.” It was not merely his doing the will of God in general, but it was the specific thing of offering his body in the place of the Jewish sacrifices; compare Philippians 2:8. Whatever part his personal obedience had in our salvation, yet the particular thing here specified is, that it was his doing the will of God by offering himself as a sacrifice for sin that was the means of our sanctification.
We are sanctified - We are made holy. The word here is not confined to the specific work which is commonly called sanctification - or the process of making the soul holy after it is renewed, but it includes everything by which we are made holy in the sight of God. It embraces, therefore, justification and regeneration as well as what is commonly known as sanctification. The idea is, that whatever there is in our hearts which is holy, or whatever influences are brought to bear upon us to make us holy, is all to be traced to the fact that the Redeemer became obedient unto death, and was willing to offer his body as a sacrifice for sin.
Through the offering of the body - As a sacrifice. A body just adapted to such a purpose had been prepared for him; Hebrews 10:5. It was perfectly holy; it was so organized as to be keenly sensitive to suffering; it was the dwelling-place of the incarnate Deity.
Once for all - In the sense that it is not to be offered again; see the notes on Hebrews 9:28. This ideals repeated here because it was very important to be clearly understood in order to show the contrast between the offering made by Christ, and those made under the Law. The object of the apostle is to exalt the sacrifice made by him above those made by the Jewish high priests. This he does by showing that such was the efficacy of the atonement made by him that it did not need to be repeated; the sacrifices made by them, however, were to be renewed every year.