A.T. Robertson Commentary Mark 13:24

"But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light," — Mark 13:24 (ASV)

The sun shall be darkened (ο ελιος σκοτισθησετα). Future passive indicative. These figures come from the prophets (Isaiah 13:9f.; Ezekiel 32:7f.; Joel 2:1f.,10f.; Amos 8:9; Zephaniah 1:14–16; Zechariah 12:12). One should not forget that prophetic imagery was not always meant to be taken literally, especially apocalyptic symbols. Peter in Ac 2:15-21 applies the prophecy of Joel about the sun and moon to the events on the day of Pentecost. See on Mt 24:29-31 for details of verses 24-27.