In the discussion of the feast of harvest, the harvest symbolizes the resurrection of the first human body who was Jesus, and the released Saints in "Sheol" who were truly believers. This release became possible through the cross. "And the feast of harvest, the firstfruits of thy labours, which thou hast sown in the field: and the feast of ingathering, [which is] in the end of the year, when thou hast gathered in thy labours out of the field." (Exodus 23:16)
Leviticus 23:17-21 explains how Pentecost should be understood. God spells out the offering He requires of the Jews for their sins which teaches why God finally offered His Son. There was no other way His Church could be redeemed. The Gentiles were not under the Levitical priesthood, nor their laws.
The blood sacrifice had to be satisfied once and for all in Christ Jesus to redeem His Body, the Church - Jewish and Gentiles, who receive Him as their King. Already in the Old Testament the promise of the firstfruits consisting of Jews and Gentiles is born out by the two loaves of leaven bread in Leviticus 23:17-21:
Under the Levitical Law, "Ye shall bring out of your habitations two wave loaves of two tenth deals: they shall be of fine flour; they shall be baken with leaven; [they are] the firstfruits unto the LORD. And ye shall offer with the bread seven lambs without blemish of the first year, and one young bullock, and two rams: they shall be [for] a burnt offering unto the LORD, with their meat offering, and their drink offerings, [even] an offering made by fire, of sweet savour unto the LORD.
"Then ye shall sacrifice one kid of the goats for a sin offering, and two lambs of the first year for a sacrifice of peace offerings. And the priest shall wave them with the bread of the firstfruits [for] a wave offering before the LORD, with the two lambs: they shall be holy to the LORD for the priest. And ye shall proclaim on the selfsame day, [that] it may be an holy convocation unto you: ye shall do no servile work [therein: it
shall be] a statute for ever in all your dwellings throughout your generations." (Leviticus 23:17-21)
[He is speaking to Israel] In Deuteronomy 16:10-14 (Old Testament, Israel was admonished to observe the "Feast of Tabernacles" which represents God's dwelling place, now the church, Jesus' body, which was born on Pentecost. Jesus' body began with Jesus Himself. He referred to Himself as the temple. (see John 2:21)
The harvest represents the crucifixion on Passover of which Jesus Christ is the First
Fruits. Solomon left no doubt that these feasts were important to God and confirmed once again in 2 Chronicles 8:12,13 "Then Solomon offered burnt offerings unto the LORD on the altar of the LORD, which he had built before the porch,
"Even after a certain rate every day, offering according to the commandment of Moses, on the sabbaths, and on the new moons, and on the solemn feasts, three times in the year, [even] in the feast of unleavened bread, and in the feast of weeks, and in the feast of tabernacles." (2Chronicles 8:12,13)
In Acts chapter two, the birth of the Church is described as an event, the feast of tabernacles. This celebration will be resumed during the millennium when God requires people to come toJerusalem annually to celebrate with Him.