The first man is of the earth, earthy: the second man is the Lord from heaven. The first man is of the earth - That is: Adam's body was made out of the dust of the earth; and hence the apostle says he was χοΐκος, of the dust; for the body was made עפר מן האדמה aphar min haadamah, dust from the ground; Genesis 2:7.
The second man is - from heaven - Heavenly, ουρανιος, as several good MSS. and versions read. The resurrection body shall be of a heavenly nature, and not subject to decay or death. What is formed of earth must live after an earthly manner; must be nourished and supported by the earth: what is from heaven is of a spiritual nature; and shall have no farther connection with, nor dependence upon, earth. I conceive both these clauses to relate to man; and to point out the difference between the animal body and the spiritual body, or between the bodies which we now have and the bodies which we shall have in the resurrection. But can this be the meaning of the clause, the second man is the Lord from heaven? In the quotation I have omitted ὁ Κυριος, the Lord, on the following authorities: Manuscripts - BCD*EFG, and two others. Versions - Coptic, Ethiopic, Armenian in the margin, Vulgate, and Itala. Fathers-Origen, who quotes it once and omits it once; Athanasius, Basil, the two Gregories, Nyssen and Nazianzen; Isidore, Cyril, Tertullian, Cyprian, Hilary, Zeno, Ambrose, Augustine, Jerome, Ambrosiaster, Philaster, Leo, Pacianus, Primasius, Sedulius, Bede, and others. See these authorities more at large in Wetstein. Some of the most eminent of modern critics leave out the word, and Tertullian says that it was put in by the heretic Marcion. I do think that the word is not legitimate in this place. The verse is read by the MSS., versions, and fathers referred to, thus: The first man is of the earth, earthy; the second man is of heaven, heavenly; Κυριος being omitted and ουρανιος added. The first man and the second man of this verse are the same as the first Adam and the second Adam of 1 Corinthians 15:45, and it is not clear that Christ is meant in either place. Some suppose that there is a reference here to what Eve said when she brought forth Cain: I have gotten a man from the Lord, קניתי איש את יהוה kanithi ish eth Yehovah, I have possessed or obtained a man, the Lord; that is, as Dr. Lightfoot explains it, that the Lord himself should become man: and he thinks that Eve had respect to the promise of Christ when she named her son; as Adam had when he named his wife. If Eve had this in view, we can only say she was sadly mistaken: indeed the conjecture is too refined.
The terms first man of the earth, and second man from heaven, are frequent among the Jews: אדם לעילא the superior Adam; and אדם תתאה Adam the inferior; that is, the earthly and the heavenly Adam: Adam before the resurrection, and Adam after it.