For both he that sanctifieth (i.e. Christ, the ἀρχηγὸς) and they that are sanctified (i.e. the "many sons" who are brought unto glory) are all of one ( ἐξ ἑνὸς, i.e. of God). The idea expressed here by the verb ἁγιάζω, to sanctify, may be determined by comparison with Hebrews 9:13, Hebrews 9:14; Hebrews 10:14, Hebrews 10:29; and Hebrews 13:12 ( ἵνα ἁγιάση διὰ τοῦ ἰδίου αἱμάτος τὸν λαόν); cf.
John 17:9. It is not the idea, to us most familiar, of moral sanctification through the Holy Spirit, but that of the redeemed being brought into a new relation to God, hallowed for "glory," through redemption; whence all Christians are called ἅγοι.
ἁγιάζειν is the equivalent in the LXX. of the Hebrew שׂדַקָ, which is applied to the hallowing of both the sacrifices and the people to God's service. As an atoning sacrifice, Christ thus hallowed himself (John 17:19), that thus he might hallow the "many sons."
ἐξ ἑνός must certainly be taken as referring to God, not (as some take it) to Abraham or Adam. For the necessity of the SON taking part of flesh and blood in order to accomplish the redemption is not introduced till John 17:14.
So far the common fatherhood spoken of has been that of him "for whom are all things and by whom are all things," who, "in bringing many sons to glory," has perfected "the Captain of their salvation."
The idea is that it was meet that the Captain should be perfected through human sufferings, since both he and the "many sons" are of one Divine Father; in their relation of sonship (with whatever difference of manner and degree) they are associated together.
Be it observed, however, that it is not the original relation to God of the "Sanctifier" and the "sanctified," but their relation to him in the redemption, that is denoted by ἐξ ἑνός. The common sonship does not consist in this, that he is Son by eternal generation and they by creation.
It has been seen above that the term υἵος is net applied to Christ in this Epistle with reference to his eternal Being, but to his incarnation; and the human "sons" are not regarded as such till made so by redemption.
ὁ ἁγιάζων, and οἳ ἁγιαζομένοι rule the sense of ἐξ ἑνός. The view is that the one Father sent the SON into the world to be the Firstborn of many sons. The expression, frequent in the Pentateuch, "I am he that sanctifieth," may be cited in illustration of the moaning of the passage.
For which cause he is not ashamed to call them brethren; i.e. in the Messianic utterances of the Old Testament, to which, in accordance with the plan and purpose of the Epistle, reference is again made for proof.
The point of the quotations that follow (John 17:12, John 17:13) is that the Messiah, notwithstanding the position above the angels, shown above to be assigned to him, is represented also as associating himself with men as brethren, in dependence on one heavenly Father.