en_tn/rev/07/14.md

have come out of the great tribulation

"have survived the great tribulation" or "have lived through the great tribulation"

the great tribulation

"the time of terrible suffering"

They have washed their robes and made them white in the blood of the Lamb

People who have been made righteous by the blood of the Lamb are spoken of as if they have washed their robes in his blood. Alternate translation: "They have been made righteous by washing their robes white in his blood" (See: rc://en/ta/man/translate/figs-metaphor)

the blood of the Lamb

The word "blood" is used to refer to the death of Lamb. (See: rc://en/ta/man/translate/figs-metonymy)