Thomas Aquinas — on Eph 4:8-9 (Question 52. Christ's descent into hell, Article 1)

“Since it was fitting for Christ to die in order to deliver us from death, so it was fitting for Him to descend into hell in order to deliver us also from going down into hell. Hence it is written (Hosea 13:14): "O death, I will be thy death; O hell, I will be thy bite." Secondly, because it was fitting when the devil was overthrown by the Passion that Christ should deliver the captives detained in hell, according to Zechariah 9:11: "Thou also by the blood of Thy Testament hast sent forth Thy prisoners out of the pit."”