Pentecost celebrated the enactment of the Old Covenant between God and Israel. It occurred on the fiftieth day following the weekly Sabbath within the eight day Passover Festival. The first day which counted toward Pentecost or the Feast of Weeks was always a Sunday. Its date varied, hence the need to count. This Sunday was the day the Wave Sheaf Offering was lifted up to be received of God, and in its offering the whole harvest was made holy to the Lord. Nothing in the fields could be harvested until this offering was made.
It was on the day of the Wave Sheaf Offering that Jesus, arose from the dead, offered himself to God to be accepted as our Representative. Thus, in Jesus, the spiritual harvest is both begun and is blessed.
Pentecost occurred fifty days afterward. It was a time of celebration of all that God had done, and on the first Pentecost (Feast of Weeks) it celebrated Israel’s coming out of Egypt and the establishment of the Mosaic Covenant at Sinai with Almighty God. Similarly, in the New Testament Pentecost celebrates all that God had done through Jesus and the coming of the Holy Spirit, who mightily took out of Israel the beginning of the firstfruits for Jesus. Thus, the Kingdom of God had begun to be established in the realm of mankind.
It began with the sound of a rushing mighty wind (Acts 2:2), the sort that parted the Red Sea to permit God’s people access, bringing them over the gap that no man could cross on his own (Exodus 14:21; cf. 2Samuel 22:16). The sound was that of the breath of God, brooding over his people (Genesis 1:2) and breathing life—new, eternal life—into his people who were dead in sin (cf. Genesis 2:7; Ezekiel 37:9-10; Ephesians 2:1).
The sound came from heaven (Acts 2:2), showing what was occurring came from God, and it appeared like tongues of fire (Acts 2:3; cf. Deuteronomy 33:2). What Luke is telling us is that God took some of the Spirit of our second Adam (Jesus—cf. 1Corinthians 15:45-46), and placed it upon his called out people; thus, inaugurating the New Covenant in his new spiritual creation (2Corinthians 5:17; cf. Galatians 6:15). We find a like similarity under the Old Covenant when God took of the Spirit of Moses and placed it on the 70 elders (Numbers 11:25; cf. Acts 2:4).
This was the time of the beginning of the Kingdom of God—the time when God first began to stretch forth his hand to restore all things to their original order (cf. Acts 3:21). We have been told that long ago God had come down to scatter the nations by confusing their tongues (Genesis 11:1-9), because Nimrod, the son of the cursed Cush (Genesis 10:8) had begun to gather all people to himself (Genesis 10:10; cf. 11:9), opposing the will of God to fill the earth (Genesis 1:28; 9:1). On the other hand, in Acts 2 we have understanding (v.8) and not confusion; and those scattered throughout the world (v.5) are gathered together under the blessing and call of God—not at the command of the one honored by men but cursed of God—Cush’s son, Nimrod, but at the command of the One (Jesus) rejected and slain by men, but honored by God through resurrection and his ascension to the throne of God, where he stays until he his given his own throne over all nations (cir 70 AD), and comes to judge Jerusalem. At that time the Kingdom of God will be firmly established among men, when he comes to dwell with us (Revelation 21:1-3).