Ephesians 4:9 - Descending into confusion...?

"But the “He ascended”, what is this, if not that also He descended unto the lower parts of the earth?"

-What we have here is a bonafide Pauline tangent.  He’s talking about gifts and how they relate to the overall oneness of the body, and yet Paul feels compelled to unpack a nuance of the verse from Psalms which he just quoted.

-Unfortunately, there are multiple ways to understand what Paul is attempting to clarify at this point, several more-or-less satisfactory interpretations (clarity thus becoming somewhat elusive).  The primary question concerns what precisely Paul is thinking about in saying ‘He descended’.  One version has him talking about how Christ after He died descended into Sheol (i.e. the lower parts of the earth).  This explains the leading forth of captives mentioned in Psalm 68.18, Old Testament saints who would have looked forward to a future coming of God’s Messiah providing the perfect atonement for their sins (and also is consistent with ideas found in Acts 2.31; 1Peter 3.19-20, 4.6) - in this case the descent would have taken place prior to the ascension.  Another way of understanding the descent is to suggest that Paul here is referring to the incarnation, when Christ descended from His place in the heavenlies and lowered Himself both spatially and personally by taking on flesh in the form of a suffering servant.  Another interpretation has the descent as simply Christ being buried, going from the cross to the grave.  For both of these one could still account for a leading forth of captives taking place subsequently at the time of the ascension.  Still another version suggests that Paul is referring to Christ’s Spirit descending to fill all believers at Pentecost.  Apparently Psalm 68 was associated with Pentecost in traditional Jewish liturgy.  This fourth explanation can mesh well with verse 10, but is somewhat less satisfying for this writer, because it certainly seems as though Paul has the same Person doing both the ascending and descending.  

-Whether one opts for a descent to earth or to the tomb or to the place of the dead depends on what one thinks is meant by the phrase, ‘the lowers [i.e. lower parts] of the earth’.  In fact this is the only place the Greek word ‘katotera’ appears in the entire NT, but it is used in the OT to translate the Hebrew word for ‘depths’ (Psalm 63.9, Psalm 86.13, Psalm 88.6, Psalm 139.15).  It can certainly refer the place of the dead, but can also mean a hidden place or a place of despair.  The next verse may provide some greater clarity, but the point here is that there is no ascension (anabas) without a prior descension (katabas).