The people harvested in the Barley Harvest are called "overcomers". They will be those who are the "sealed of Yahweh". Their robes will be white because they didn't get stained.
Revelation 3:4-5
Thou hast a few names even in Sardis which have not defiled their garments; and they shall walk with me in white: for they are worthy. He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels.
These are the 144,000 who were not defiled:
Revelation 14:4
These are they which were not defiled with women; for they are virgins. These are they which follow the Lamb whithersoever he goeth. These were redeemed from among men, being the firstfruits unto Yahweh and to the Lamb.
Also, part of the barley harvest will be the martyrs who will be resurrected. They will be given new white robes:
Revelation 6:9-11
And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of Yahweh, and for the testimony which they held: And they cried with a loud voice, saying, How long, O Yahweh, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth? And white robes were GIVEN unto every one of them; and it was said unto them, that they should rest yet for a little season, until their fellowservants also and their brethren, that should be killed as they were, should be fulfilled.
After the barley harvest (at the 2nd coming of Christ), we have two groups in Heaven, the restored martyrs and the undefiled. They sit on thrones and rule with Christ for a 1000 years.
Revelation 20:4-6
And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Yahushua [Jesus], and for the word of Yahweh, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection. Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of Yahweh and of Christ, and shall reign with him a thousand years.
This is the barley harvest. If there were no later harvest, over whom would they rule? For whom would they exercise their priestly duties?
Clean, white robes are either given to the martyrs or worn already clean, by the overcomers. These are the barley harvest robes. Thankfully, Christ has more saving yet to perform - the wheat and the grapes.
