For what son is he, etc. He reasons from the common practice of men, that it is by no means right or meet that God's children should be exempt from the discipline of the cross; for if no one is to be found among us, at least no prudent man and of a sound judgment, who does not correct his children -- for without discipline they cannot be led to a right conduct -- how much less will God neglect so necessary a remedy, who is the best and the wisest Father? If any one raises an objection, and says that corrections of this kind cease among men as soon as children arrive at manhood: to this I answer, that as long as we live we are with regard to God no more than children, and that this is the reason why the rod should ever be applied to our backs. Hence the Apostle justly infers, that all who seek exemption from the cross do as it were withdraw themselves from the number of his children. It hence follows that the benefit of adoption is not valued by us as it ought to be, and that the grace of God is wholly rejected when we seek to withdraw ourselves from his scourges; and this is what all they do who bear not their afflictions with patience. But why does he call those who refuse correction bastards rather than aliens? Even because he was addressing those who were members of the Church, and were on this account the children of God. He therefore intimates that the profession of Christ would be false and deceitful if they withdrew themselves from the discipline of the Father, and that they would thus become bastards, and be no more children. [1]

Footnotes

1 - There is in this verse the word "sons," to be understood after "all;" that is, "all the sons are partakers:" so Macknight and Stuart. As "sons" conclude the verse, the word is omitted here. Those who have only the name of Christians are called "bastards," or spurious or illegitimate children, because they are not born of God, being only the children of the flesh. They are not Isaac's but Ishmael, whatever their professions may be, and though baptized and partakers of all the outward privileges of the gospel. -- Ed.

If ye endure chastening - That is, if you undergo, or are called to experience correction. It does not mean here, "if you endure it patiently; or if you bear up under it;" but "if you are chastised or corrected by God." The affirmation does not relate to the manner of bearing it, but to the fact that we are disciplined.
God dealeth with you as with sons - He does not cast you off and regard you as if you were in no way related to him.
For what son is he whom the father chasteneth not - That is, he evinces toward his son the care which shows that he sustains the relation of a father. If he deserves correction, he corrects him; and he aims by all proper means to exhibit the appropriate care and character of a father. And as we receive such attention from an earthly parent, we ought to expect to receive similar notice from our Father in heaven.

If ye endure chastening - If ye submit to his authority, humble yourselves under his hand, and pray for his blessing, you will find that he deals with you as beloved children, correcting you that he may make you partakers of his holiness.
God dealeth with you as with sons - He acknowledges by this that you belong to the family, and that he, as your Father, has you under proper discipline. It is a maxim among the Jewish rabbins that "the love which is not conjoined with reproof is not genuine."

If ye endure chastening,.... In faith, with patience, with courage and constancy, with humility and reverence: there are many things which may encourage and animate the saints to endure it in such a manner; as that it is but a chastening, and the chastening of a father; it should be considered from whence it comes, and for what ends; that it comes from the Lord, and is for his glory, and their good; the example of Christ, and of other saints, should excite unto it. The Jews have a saying (q), that
"the doctrine of chastisements is silence;''
that is, they are to be patiently bore, and not murmured at. The Vulgate Latin, and all the Oriental versions, read the words as an exhortation; the former of these renders it, "persevere in discipline"; the Syriac version, "endure correction"; the Arabic version, "be ye patient in chastisement"; and the Ethiopic version, "endure your chastening": but then the word, "for", should be supplied in the next clause, as it is in the Syriac and Ethiopic versions, making that to be a reason, enforcing this,
for God dealeth with you as with sons: chastening is owning of them for his children, and it discovers them to be so, and shows that they continue such; he does not chasten them but when it is necessary; and whenever he does, it is in love and mercy, and for good, and in the best time, seasonably, and in measure:
for what son is he whom the father chasteneth not? no one can be named, not the Son of God himself; he had the chastisement of our peace upon him; nor the more eminent among the children of God, as Abraham, David, and others; nor any in any catalogue, or list of them, such as in the preceding chapter; not one in any age or period of time whatever, in any bodies, societies, or communities of them, either under the Old or New Testament.
(q) T. Bab. Beracot, fol. 62. 1.

In Hebrews 12:7-8 the need of "chastening" or "discipline" is inculcated; in Hebrews 12:9, the duty of those to whom it is administered.
If--The oldest manuscripts read, "With a view to chastening (that is, since God's chastisement is with a view to your chastening, that is, disciplinary amelioration) endure patiently"; so Vulgate. ALFORD translates it as indicative, not so well, "It is for chastisement that ye are enduring."
dealeth with you--"beareth Himself toward you" in the very act of chastening.
what son is he--"What son is there" even in ordinary life? Much more God as to His sons (Isaiah 48:10; Acts 14:22). The most eminent of God's saints were the most afflicted. God leads them by a way they know not (Isaiah 42:16). We too much look at each trial by itself, instead of taking it in connection with the whole plan of our salvation, as if a traveller were to complain of the steepness and roughness of one turn in the path, without considering that it led him into green pastures, on the direct road to the city of habitation. The New Testament alone uses the Greek term for education (paideia), to express "discipline" or correction, as of a child by a wise father.

Whom his father chasteneth not - When he offends.