KJV:
Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life.
NASB:
'Do not fear what you are about to suffer. Behold, the devil is about to cast some of you into prison, so that you will be tested, and you will have tribulation for ten days. Be faithful until death, and I will give you the crown of life.