The Firstfruits of the Resurrection
After the weekly Sabbath, which ended on Saturday at sundown, the women returned to the tomb with the spices they had prepared. Mary Magdalene arrived before the others and it was still dark when she arrived. She could have arrived at the tomb any time on Sunday before first light. Whenever that was, the tomb was already empty and open. Jesus had fulfilled the full three days and three nights in the tomb as of sunset on Saturday, the 17th of Nisan.
Mary ran to tell Peter and then returned with him. The other women arrived and they all witnessed the empty tomb. Some saw and spoke with a heavenly messenger. The message being clear, "he is not here, but was raised" (Luke 24:6 YL T). The Young's Literal Translation putting the verb in past tense, "but was raised". Same with the messenger in Matthew 28: "Fear not ye, for I have known that Jesus, who hath been crucified, ye seek; he is not here, for he rose, as he said; come, see the place where the Lord was lying" (Matthew 28:5-6 YL T).
Now here is something amazing; nearly 1500 years earlier, Jehovah commanded the High Priest to present a wave offering, or sometimes called the sheaf offering, wave sheaf, or first sheaf. It is an offering of firstfruits before the Lord in the temple on the day after the first weekly Sabbath after the Passover (Leviticus 23:10-11, 16) to be presented that all the harvest to follow would be acceptable before the Lord.
The firstfruits offering is made of finely ground barley grain (flour), oil, and wine. The grain was the first to rise from the earth. Flour, like bread for the body, wine for the blood, oil for the spirit. The offering is raised up before the Lord and then placed on the altar. Each of these ingredients finds its use through being crushed and refined. Jesus is foremost among those who are crushed, refined, and raised.
Jesus told Mary there at the tomb that he had not yet ascended to His Father, but to go and tell the others that this is what was about to happen. Just at the time the High Priest would be in the temple raising the first sheaf before the Lord that all the follow would be acceptable before the Lord, the Lord himself would be ascending to His Father to present himself as the first sheaf and that all who follow him may be acceptable too (and many did follow and many graves were opened after His as well).
How many ways God provided for His son to be recognized by the people. He made it as easy as possible for those who were paying attention. Paul recognized this pattern. He said, "But now is Christ risen from the dead, and become the firstfruits of them that slept." (1 Cor 15:20)
Feast of Weeks, The Days of Counting, and Pentecost
The purpose of Passover and exodus from Egypt was to enable Israel to prepare themselves to receive the Law 50 days later on Shavuot (the Feast of Weeks). The Lord commanded Israel, "You shall count fifty days to the day after the seventh Sabbath. Then you shall present a grain offering of new grain to the Lord" (Lev 23:15-16), "Seven weeks you shall count for yourself, then you shall keep the festival of Shavuot to the Lord" (Deut 16:9-10).
These seven weeks point to a period of preparing oneself. Count for yourself, then come before the Lord. During this seven weeks Israel was invited to prepare themselves for Sinai, to sanctify themselves, and to receive a higher law. Moses tried to prepare a sanctified people who could see God on Sinai. They rejected this offer.
Fast forward to that same day 50 days after the resurrection. The disciples and believers were gathered at the temple. This was to become the day of Pentecost. Just as Israel was to be sanctified and receive the Law, the disciples during these 50 days were to tarry at Jerusalem and wait to be endowed with power from on high. This day, the spirit was poured out on the people with a sound as of a rushing mighty wind. Some saw tongues of fire resting on the apostles. Others spoke in foreign languages. The experience points to the official establishment of a new law.