Who hath also given. That he may the more effectually turn away the Thessalonians from such contempt and obstinacy, he reminds them that they had been endowed with the Spirit of God, first, in order that they may distinguish what proceeds from God; secondly, that they make such a difference as is befitting between holiness and impurity; and thirdly, that, with heavenly authority, they may pronounce judgment against all manner of unchastity -- such as will fall upon their own heads, unless they keep aloof from contagion. Hence, however wicked men may treat with ridicule all instructions that are given as to a holy life and the fear of God, those that are endowed with the Spirit of God have a very different testimony sealed upon their hearts. We must therefore take heed, lest we should extinguish or obliterate it. At the same time, this may refer to Paul and the other teachers, as though he had said, that it is not from human perception that they condemn unchastity, but they pronounce from the authority of God what has been suggested to them by his Spirit. I am inclined, however, to include both. Some manuscripts have the second person -- you, which restricts the gift of the Spirit to the Thessalonians.

He therefore that despiseth - Margin, "rejecteth." That is, he who disregards such commands as these which call him to a holy life, is really rejecting and disobeying God. Some might be disposed to say that these were merely the precepts of man, and that therefore it was not important whether they were obeyed or not. The apostle assures them in the most solemn manner, that, though communicated to them by man, yet they were really the commands of God.
Who hath also given unto us his holy Spirit - This is a claim to inspiration. Paul did not give these commands as his own, but as taught by the Spirit of God; compare notes on 1-Corinthians 7:40.

He therefore that despiseth - He who will not receive these teachings, and is led either to undervalue or despise them, despises not us but God, from whom we have received our commission, and by whose Spirit we give these directions. See Clarke's note on 1-Thessalonians 4:15.
Hath also given unto us his Holy Spirit - Instead of εις ἡμας, unto Us, εις ὑμας, unto You, is the reading of BDEFG, a great many others, the Syriac, all the Arabic, Armenian, later Syriac in the margin, some of the Itala, Clement, Didymus, and Ambrosiaster; this seems to be the better reading. God has taught us that we may teach you; and he has also given you his Holy Spirit that ye might understand and be enabled to practice these things. It is one thing to receive a revelation from the Spirit of God; it is another thing to receive that Spirit to enable a man to live according to that revelation. In the first sense the apostles alone received this Holy Spirit; in the latter sense all true Christians, as well as the Thessalonians, receive it. I think ὑμας, you, is the true reading, and that it is confirmed by the following verse: For ye yourselves are Taught of God to love one another. Griesbach has inserted it in the margin, but has not admitted it into the text, because it has not what he deemed full support from those MSS. which are of the Alexandrian recension; but he thought its genuineness very probable.

He therefore that (c) despiseth, despiseth not man, but God, who hath also given unto us his holy Spirit.
(c) These commandments which I gave you.

He therefore that despiseth,.... The Vulgate Latin adds, "these things"; these exhortations now delivered, the commandments given by the Lord Jesus Christ, and the will of God above declared; he that rejects these things with contempt, takes no notice of them, and acts not according to them,
despiseth not man; not men only, the apostles of Christ, and ministers of the Gospel; for, by despising these exhortations, they themselves were despised, though not alone: but God; Father, Son, and Spirit; God the Father, whose will was their sanctification, even to abstain from fornication, and every act of uncleanness, which, if not attended to, was a despising of him; and the Lord Jesus Christ, by whom, and for whose sake they were entreated and exhorted, and in whose name, and by whose authority the apostle gave them these commandments; wherefore to slight them, was to slight Jesus Christ himself; and, by the way, this is a proof of the true and proper deity of Christ. Moreover, such despisers also, in some sense, do despite unto the spirit of grace, by whom the apostles spake, or who spoke in them these things, as follows,
who hath also given unto us his Holy Spirit; as he did to the prophets of the Old Testament, and therefore what they said was equally by divine inspiration of God; and hence despising them, was despising the Spirit of God that spake by them. The Syriac and Arabic versions read, "who hath given unto you his Holy Spirit"; and so all Stephens's copies; which furnishes out a fresh reason or argument, dissuading from uncleanness, since God had given them his "Spirit" to convince them of sin, of righteousness, and of judgment, so that they were not ignorant of the things warned against; and he had given them his Spirit as an "holy" Spirit, as a Spirit of sanctification, to begin and carry on that work in them, to which uncleanness was very opposite; and he had given his Spirit unto, or "into" them, to dwell in them, as in his temple, and therefore should be careful not to defile it; and to cause them to walk in his statutes, and to assist them to keep his judgments, and do them, and as an earnest of their inheritance, and a sealer of them up unto the day of redemption; wherefore it became them not to grieve him by an impure life; and they were laid under obligations to live in the Spirit, and to walk after him, and not after the flesh.

despiseth, &c.--Greek, "setteth at naught" such engagements imposed on him in his calling, 1-Thessalonians 4:7; in relation to his "brother," 1-Thessalonians 4:6. He who doth so, "sets at naught not man (as for instance his brother), but God" (Psalm 51:4) is used of despising or rejecting God's minister, it may mean here, "He who despiseth" or "rejecteth" these our ministerial precepts.
who hath also given unto us--So some oldest manuscripts read, but most oldest manuscripts read, "Who (without 'also') giveth (present) unto you" (not "us").
his Spirit--Greek, "His own Spirit, the Holy (One)"; thus emphatically marking "holiness" (1-Thessalonians 4:7) as the end for which the Holy (One) is being given. "Unto you," in the Greek, implies that the Spirit is being given unto, into (put "into" your hearts), and among you (compare 1-Thessalonians 2:9; Ephesians 4:30). "Giveth" implies that sanctification is not merely a work once for all accomplished in the past, but a present progressive work. So the Church of England Catechism, "sanctifieth (present) all the elect people of God." "His own" implies that as He gives you that which is essentially identical with Himself, He expects you should become like Himself (1-Peter 1:16; 2-Peter 1:4).

He that despiseth - The commandments we gave. Despiseth God - Himself. Who hath also given you his Holy Spirit - To convince you of the truth, and enable you to be holy. What naked majesty of words! How oratorical, and yet with what great simplicity! - a simplicity that does not impair, but improve, the understanding to the utmost; that, like the rays of heat through a glass, collects all the powers of reason into one orderly point, from being scattered abroad in utter confusion.