As the Passover lambs were being slaughtered, a band of priests would go to the barley fields and identify the barley that would be offered to Yahveh on the feast of First Fruits, which according to Scripture is celebrated on the morning after the weekly Sabbath following Passover. The best of the standing barley was tied into sheaves but not harvested. When this was accomplished, the priests would hurry back to Yerushalayim to prepare to eat the Passover. When the Sabbath following Passover ended at sunset on Saturday, the standing sheaves of barley were harvested and taken to the Temple where they were
processed into the finest barley flour during the night. On Sunday morning, the First Fruits were presented to the Yahveh in the Temple. As the priests were identifying the First Fruits of the barley harvest by tying up the sheaves in the fields, Y'shua died.
Scripture tells us that at that moment, the sun stopped shining, the earth quaked, the veil of the Temple was ripped from top to bottom and graves were opened. After Y'shua was raised from the dead, the occupants of the opened graves were resurrected and many were seen in Yerushalayim. When Mary saw the resurrected Messiah on Sunday morning He told her, “Stop clinging to Me, for I have not yet ascended to the Father; but go to My brethren and say to them, 'I ascend to My Father and your Father, and My God and your God.'" (John 20:17 NASB). Most Christians do not know that Y'shua ascended to the Father on the morning of the Resurrection, nor do they know why He did so.
The graves that were opened at the moment that the First Fruits of the Barley harvest were being tied into Sheaves constituted the identification of the First Fruits of the resurrection. The resurrection of the occupants of those graves constituted the harvesting of the First Fruits of the Resurrection. The reason Y'shua had to ascend to the father early on Resurrection Sunday was to present the First Fruits of the resurrection to His Father and our Father on the Feast of First Fruits.
This is what Paul alluded to when he wrote: “But now Christ has been raised from the dead, the first fruits of those who are asleep. For since by a man came
death, by a man also came the resurrection of the
dead. For as in Adam all die, so also in Christ all will be made alive. But each
in his own order: Christ the first fruits, after that those who are Christ's at
His coming…”(1 Corinthians 15:20-23 NASB).