Revelation 6:11
"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."
Cross References (ranked by relevance)
And I heard a voice from heaven saying unto me, Write, Blessed are the dead which die in the Lord from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.
After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb.
God having provided some better thing for us, that they without us should not be made perfect.
But go thou thy way till the end be: for thou shalt rest, and stand in thy lot at the end of the days.
They shall put you out of the synagogues: yea, the time cometh, that whosoever killeth you will think that he doeth God service.