8:3 {4} For every high priest is ordained to offer gifts and sacrifices: wherefore [it is] of necessity that this man have somewhat also to offer.
(4) He brings a reason why it must be that Christ should have a body (which he calls a tabernacle which the Lord built, and not man) that is, that he might have that to offer: for otherwise he could not be an High Priest. The body is both the tabernacle and the sacrifice.
8:3 For every high priest is ordained to offer gifts and sacrifices. It is his appointment to offer gifts and sacrifices. That is his office. Hence, if Jesus is a High Priest, he must have an offering, but his offering must be presented in the true Holy of Holies above.
8:1-6 The substance, or summary, of what had been declared was, that Christians had such a High Priest as they needed. He took upon himself human nature, appeared on earth, and there gave himself as a sacrifice to God for the sins of his people. We must not dare to approach God, or to present any thing to him, but in and through Christ, depending upon his merits and mediation; for we are accepted only in the Beloved. In all obedience and worship, we should keep close to God's word, which is the only and perfect standard. Christ is the substance and end of the law of righteousness. But the covenant here referred to, was that made with Israel as a nation, securing temporal benefits to them. The promises of all spiritual blessings, and of eternal life, revealed in the gospel, and made sure through Christ, are of infinitely greater value. Let us bless God that we have a High Priest that suits our helpless condition.
