The sun shall be darkened (o elio skotisqhsetai). Future passive indicative. These figures come from the prophets ( Isaiah 13:9 ; Ezekiel 32:7 ; Joel 2:1 Joel 2:10 ; 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 Acts 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 Acts 24-27 .