According to Isaiah 42:6-7, Christ descended into Sheol/Hades “to bring out the prisoners from the prison, and them that sit in darkness out of the prison-house.” Paradise was, in a sense, a prison to those saints who died before Christ’s death and resurrection. Ephesians 4:8 states that “when he ascended on high, he led captivity captive, and gave gifts unto men.” Paul’s statement in Ephesians 4:8 is a quote from Psalm 68:18, a victory song of David. When a conquering general returned from battle, he triumphantly paraded through his hometown with his prisoners in tow and bearing gifts. When Christ ascended into Heaven on the heels of His resurrection, He returned triumphantly to His home with His prisoners (i.e., the saints of Paradise) and bore gifts unto men.
The first day of the week, after the Passover, is also significant. It is the Feast of First-fruits, when the High Priest presented the wave offering before God, thus dedicating the whole harvest to Him. On the first day of the week, after Passover, Christ presented Himself to the Father as the First-fruits offering. As the First-fruit offering, Christ gave notice of a more substantial harvest to follow, which includes the Church Age saints at the Rapture as well as the Old Testament saints and Tribulation saints at the Return of Christ. By presenting these Old Testament saints as a First-fruits offering to the Lord, they represent a more substantial harvest of Israelites, which Christ will harvest (i.e., save) at the end of the Tribulation.