For the earnest expectation of the creature waiteth for the manifestation of the sons of God. For the earnest expectation of the creature - There is considerable difficulty in this and the four following verses: and the difficulty lies chiefly in the meaning of the word ἡ κτισις, which we translate the creature, and creation. Some think that by it the brute creation is meant; others apply it to the Jewish people; others to the godly; others to the Gentiles; others to the good angels; and others to the fallen spirits, both angelic and human. Dissertations without end have been written on it; and it does not appear that the Christian world are come to any general agreement on the subject. Dr. Lightfoot's mode of explanation appears to me to be the best, on the whole. "There is," says he, "a twofold key hanging at this place, which may unlock the whole, and make the sense plain and easy.
1. The first is the phrase, πασα ἡ κτισις, which we render the whole creation, Romans 8:22, and with which we meet twice elsewhere in the New Testament. Mark 16:15 : Preach the Gospel, πασῃ τῃ κτισει, to every creature; and Colossians 1:23 : The Gospel was preached, εν πασῃ τῃ κτισει, to every creature. Now it is sufficiently apparent what is meant by πασα κτισις in both these places, viz. all nations, or the heathen world. For that which in St. Mark is, preach the Gospel to every creature, is, in St. Matthew, go and teach, παντα τα εθνη, all nations. And this very phrase in this place lays claim to that very interpretation. And the Hebrew כל הבריות col habberioth, which answers to the Greek πασα ἡ κτισις, every creature, is applied by the Jews to the Gentiles, and that by way of opposition to Israel.
2. The second key is the word ματαιοτητι, Romans 8:20, which is not unfitly rendered vanity; but then this vanity is improperly applied to the vanishing, dying, changing state of the creation. For ματαιοτης, vanity, does not so much denote the vanishing condition of the outward state, as it does the inward vanity or emptiness of the mind. So the apostle, speaking of the Gentiles concerning whom he speaks here, tells us εματαιωθησαν, They became vain in their imaginations, Romans 1:21; and again, The Gentiles walk εν ματαιοτητι, in the vanity of their mind, Ephesians 4:17; so also, The Lord knoweth the thoughts of the wise, ὁτι εισι ματαιοι, that they are vain, 1 Corinthians 3:20. To all which let me add this farther observation, that throughout this whole place the apostle seems to allude to the bondage of the Israelites in Egypt, and their deliverance from it; with a comparison made betwixt the Jewish and the Gentile Church. When God would deliver Israel from his bondage, he challenges him for his Son, and his first-born, Exodus 4:22. And in like manner the Gentiles earnestly expect and wait for such a kind of manifestation of the sons of God, within and among themselves. The Romans, to whom the apostle writes, knew well how many predictions and promises it had pleased God to publish by his prophets, concerning gathering together and adopting sons to himself among the Gentiles; the manifestation of which sons the whole Gentile world with a neck as it were stretched out, as the word αποκαραδοκια implies, (απο, from, and καρα, the head, and δοκαω, to expect), doth now wait for." See the observations at the end of this chapter, (Romans 8:39 (note)).