The Feast of Weeks gets its name from YHWH’s instructions to count seven weeks from the Sabbath after Passover and then offer the first of the wheat harvest.

Leviticus 23:15–16 15 And ye shall count unto you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave offering; seven sabbaths shall be complete: Even unto the morrow after the seventh sabbath shall ye number fifty days; and ye shall offer a new meat offering unto YHWH
A week is called shavu’a in Hebrew, from a root word sheva that means seven. Seven is the number of holiness and completion, and the first verse of Torah has seven words. Moreover, in six days YHWH created the heavens and the earth, but on the seventh day he rested and set it apart as sacred (Gen. 2:3). The holy day of Shavuot, or “weeks,” marks the “Jubilee of Passover,” which occurs after we count 7×7 (49) days from the day following Passover. Since Shavuot occurs on the 50th day after Passover, the Greek translators of the Torah called it “Pentecost”. Shavuot marks the goal or climax of Passover season, commemorating both the anniversary of the giving of the Torah at Sinai as well as the giving of the Holy Spirit to the followers of Messiah (Acts 1:8; 2:1-4).
Through many miracles, YHWH delivered the Jewish people from slavery in Egypt, bringing them out to Himself (Exodus 19:4). When they arrived at Mount Sinai, He called them further apart to be His people. He declared that if they kept His covenant and listened to His voice, they would be His treasure and the people of His choosing from among all peoples of the earth (Exodus 19:5). The Jewish people received Him declaring, “All that YHWH has spoken we will do” (Exodus 19:8).
When YHWH gave the Torah, the Jewish people experienced a closer look at who He is. Through thunder, lightning and quaking earth, they encountered the holiness of the Almighty YHWH. Through His commandments and instructions, they saw His character and began to walk in deeper relationship with Him
Shavuot reminds us of YHWH’s holiness and the magnitude of His love for us. It is amazing that the Creator of the universe would bend down to earth, desiring to be in relationship with us, and reveal Himself through the given Word. In YHWH Ha Mashiach (the Messiah), who is the Word made flesh (John 1:14), YHWH bent toward us even further so that all who would receive Him could be reconciled to Him.

John 1:14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.
The Feast of Weeks, or Shavuot, was one of three pilgrimage Feasts in the Jewish year. Every able-bodied Jewish man was required to bring an offering from the first of his wheat harvest to the Temple in Jerusalem. At Shavuot, the Holy Spirit fell on the disciples empowering them to speak in the languages of those who had traveled to Jerusalem for this feast. That day, 3,000 people came to faith in YHWH Ha Mashiach ( the Messiah) (Acts 2).
In Hebrew, the Holy Spirit is known as the Ruach HaKodesh. The Greek, New Covenant word is paraclete, which means “called to one’s side.” The Holy Spirit is the presence of YHWH with Believers in YHWH Ha Mashiach ( the Messiah). On Shavuot at Mount Sinai, YHWH gave His law, the Torah. On the Shavuot after YHWH Ha Mashiach ( the Messiah) died, YHWH gave His Spirit to Believers and fulfilled the prophecy recorded in Jeremiah 31:31–33, in which YHWH declared He would write His law upon our hearts.

Jeremiah 31:31-33 Behold, the days come, saith YHWH, that I will make a new covenant with the house of Israel, and with the house of Judah: Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith YHWH But this shall be the covenant that I will make with the house of Israel; After those days, saith YHWH, I will put my law in their inward parts, and write it in their hearts; and will be their Elohim, and they shall be my people.
The Holy Spirit is our helper and comforter (John 16:7), interceding for us (Romans 8:26–17), and empowering us to bear witness to the truth of YHWH.

Acts 1:8
But ye shall receive power, after that the Holy Spirit is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.

He is our guide and teacher (John 16:13) and serves as YHWH’s pledge that we will spend eternity with Him (2 Corinthians 1:21–22). The Ruach HaKodesh also gives gifts to Believers for the purpose of building up one another (1 Corinthians 12:4–7).
As YHWH’s presence with us, the Holy Spirit enables us to fellowship with YHWH at any moment. Through His Spirit, we can encounter the living Elohim, experience the riches and delights of His presence (Psalm 16:11) and receive strength to meet any challenge.

Zechariah 4:6 Then he answered and spake unto me, saying, This is the word of YHWH unto Zerubbabel, saying, Not by might, nor by power, but by my spirit, saith YHWH of hosts.