6:11Then each of them was given a white robe, and they were told to wait a little longer, until the full number of their fellow servants, their brothers and sisters,[e] were killed just as they had been.
Then each of them was given a white robe,
The white robes are symbolic of their righteous deeds and imputed righteousness by their faith in Christ. We see these souls again in Revelation 7:9. Here they are given their robes; in chapter 7, they are standing around the throne in their white robes giving honor and praise to the One whose blood 'washed their robes', Revelation 7:14.
From physics, white light is the combination of all the colors of light; in a sense, white denotes all radiated energy. This indicates that heaven, since white is the prevalent color, may be a very large concentration of energy. We also know that when material is in close proximity to a source of energy that some of that energy is gained by the material. An example of this is heating a rod of iron; the longer it stays in "the fire" the "whiter" it glows.
So, too, after Moses came back to earth after talking with God, he had to place a veil over his face to not frighten the people, Exodus 34:29-35. When Christ was transfigured before the three disciples, Mark 9:2-8, Christ's garments became radiant and "exceedingly white". Everyone who has had a glimpse of the radiance and majesty comes away TOTALLY changed (2 Peter 1:16-18). Are you looking forward to an encounter like this?
and they were told to wait a little longer,
What is time to an eternal God? So a little while longer may be a long time for us.
until the full number of
Everything has a time and place in God's timetable. And the recompensing of deeds, 2 Corinthians 5:1-10, whether good or bad WILL take place!
[e] The Greek word for brothers and sisters (adelphoi) refers here to believers, both men and women, as part of God’s family; also in 12:10; 19:10.