"And We have not made the keepers of the Fire except as angels"—meaning, who can withstand them? "And We have not made their number except as a trial"—meaning a tribulation— "for those who disbelieve, that those who were given the Scripture may be certain"—because they find in their scriptures [the number] nineteen— "and that those who have believed may increase in faith"—meaning in attestation— "and that they may not doubt."