Ephesians 4:9-12 What does "he went up" mean, except that he had first gone down to the under parts of the earth?

Goodspeed⁽ⁱ⁾ ⁹ What does "he went up" mean, except that he had first gone down to the under parts of the earth? ¹⁰ It is he who went down who has also gone up above all the heavens, to fill the universe. ¹¹ And he has given us some men as apostles, some as prophets, some as missionaries, some as pastors and teachers, ¹² in order to fit his people for the work of service, for building the body of Christ,