“By the which will we are sanctified through the offering of the body of Jesus Christ once for all.”
King James Version (KJV)
10:10 By which will - Of God, done and suffered by Christ. We are sanctified - Cleansed from guilt, and consecrated to God.
Heb 10:10 By which will we are sanctified. By this complete submission our sins are removed from us and we are made holy. The meaning of "sanctified" here is remission of sin. Through the offering of the body of Jesus Christ. In Christ's surrender his body was offered on the cross, once [for all] for sin, and by that offering our sins are remitted.