Paul pauses, inside a parenthesis, to draw out what one word in the psalm implies. If Christ "ascended," He must first have come down. Barnes is careful here: it is not certain, he says, that Paul meant the word "ascended" proves a previous descent, but Paul probably means that in Christ's case there was, in fact, a descent first. The question makes the readers connect the reigning Christ who gives gifts with the Christ who first came low. It also prepares for the answer that they are one and the same person (Ephesians 4:10).

Paul answers his own question in the next line: "He that descended is the same also that ascended up far above all heavens, that he might fill all things" (Ephesians 4:10). The parenthesis then closes, and Paul returns to the gifts: "And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers" for "the edifying of the body of Christ" (Ephesians 4:11-12).

Paul is drawing on Psalm 68:18: "Thou hast ascended on high, thou hast led captivity captive." The verbs are a pair in Greek: anebe, "he went up," and katebe, "he came down." "The lower parts of the earth" is katotera mere, "lower regions." Barnes notes that some have understood this of the grave, and others of the region of departed spirits, "but these interpretations do not seem to be necessary." He takes it to mean "the lowest state of humiliation": the Redeemer left heaven and "became a man of humble rank and condition." Gill thinks it may rather mean "the whole of his humiliation," beginning with "his descent from heaven and incarnation," though he also mentions Christ's being in the grave, and points to Psalm 139:15, where "the lowest parts of the earth" describes a child being formed, which the Targum (an ancient Aramaic translation) applies to the mother's womb.

This question shows that the One who now rules over all is the same One who came all the way down. Before Christ rose "far above all heavens" (Ephesians 4:10), He descended. The path of glory went through humiliation. Paul does not stop to explain every detail of the descent, and commentators read "the lower parts of the earth" differently. But Barnes takes the main point to be Christ's coming down from heaven into our condition, and Gill thinks this may be the meaning.

The purpose of the whole movement is giving. He ascended "that he might fill all things" (Ephesians 4:10), and from that height He gives gifts to His people for building up His body (Ephesians 4:11-12). Gill says Christ ascended to fill His people "with his grace and righteousness, with his Spirit." The gifts every believer has received come from a Savior who first stooped low.