Zechariah was shown what would occur right after Messiah rose again from the dead. After His human body was resurrected during the night, the women came to the tomb while it was still dark, and found it empty. After dawn, Messiah appeared to Mary Magdalene, and when she tried to hold onto Him, He told her not to do that, for He had not yet ascended to His Father (He had not yet received His glorified body).
He ascended right after that, and that is the scene that Zechariah 3 describes. The Holy Spirit tells us that Yahoshua the High Priest (the Spirit tells us Messiah’s name there) stood before the Father, the Holy Spirit, and Satan, and Satan started accusing Yahoshua as He stood there in His human body. He had given His clean garment to His bride (covering her in His righteousness), and took her filthy one upon Himself.
The Father rebukes Satan, and reveals exactly where Yahoshua had been when He asks, “Is this not a brand plucked from the fire?” Of course, the Passover Seder teaches the same thing—that Yahoshua took His bride’s sin to hell, and suffered the punishment of hell’s flames in her place.
The Father then commands that Yahoshua be clothed in a clean garment—His glorified body.
The same was done with the OT saints who resurrected with Him, and were seen walking around Jerusalem. In Zechariah 3:8, they are His friends who were with Him. Remember that, in John 3:13, no human had ever ascended to heaven at that point, but now, Yahoshua’s friends were with Him in heaven. They are the friends of the Bridegroom, and also the Firstfruits wave offering of the barley harvest, which began with Messiah’s resurrection on the Feast of Firstfruits.
After Messiah received His glorified body, He returned to the earth, but He did not reveal Himself to the whole world at that point, only to His followers.
He was here for 40 days after His resurrection before ascending back to the Father, and then, nine days later was the Feast of Weeks (Acts 2), which is when the seal of the Holy Spirit was given as the New Covenant, establishing Messiah’s bride on earth. As the Bridegroom cannot have physical contact with His bride once He goes to His Father’s house to prepare their dwelling, the Holy Spirit was given in His place. His seal is the covenant of marriage to Messiah’s bride–the promise, or guarantee, that He will come for her to take her to the wedding chamber to complete the marriage.
That is the reason the veil was torn in the temple, because the temple is a foreshadow of the bride, and she was now going to be revealed on the earth. Who is it that wears a veil? The bride.
The fulfillment of the Feast of Weeks established the bride, and reveals that the ancient Jewish people receiving the physical covenant (Ten Commandments) was a foreshadow (a picture) of Messiah’s bride receiving the spiritual covenant (seal of the Holy Spirit).
That is why the laws separating Jews and Gentiles (clean vs unclean laws) were abolished, for the real substance had been revealed, making the two groups one. There is no longer physical Jew or Gentile in Messiah, for the real substance is spiritual, not physical; therefore, there is no purpose for any laws keeping the two separate, which was the entire purpose of the clean vs. unclean laws (and that includes the dietary laws).
For more information: For Whom Did Christ Die?