In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
The last trump - at the sounding of the trumpet on the last day (Matthew 24:31; 1 Thessalonians 4:16). Or, the Spirit hints that the other trumpets mentioned subsequently in the Apocalypse shall precede, and that this shall be the last (cf. Isaiah 27:13; Zechariah 9:14). As the law was given with the sound of a trumpet, so the final Judgment according to the law (Hebrews 12:19: cf. Exodus 19:16). As the Lord ascended "with the sound of a trumpet" (Psalms 47:5), so He shall descend (Revelation 11:15). The trumpet convoked the people on solemn feasts, especially on the first of the seventh month (the type of the completion of time: seven indicating perfection): on the tenth was the atonement, and on the fifteenth the feast of tabernacles, commemorative of completed salvation out of spiritual Egypt (cf. Psalms 50:1-7; Zechariah 14:18-19). Compare, His calling Lazarus from the grave "with a loud voice," John 11:43, with John 5:23; John 5:28.
The trumpet shall sound, and - immediately, in consequence.