Verses 23-25: the Feast of Trumpets EV 23:23-25{on the First Day of the Seventh Month, Which Is the Time of Grape Harvest, Jehovah's People Are to Observe the Feast of Blowing of Trumpets

Prophetically, it will be a time of Israel's moral awakening. (See also Num. 10:2.) After the assembly has been caught up and taken out of this world to be with Christ in the Father's house, God will by His Spirit start working afresh in the hearts of His ancient people, the Jews. The blast of a trumpet is the figure used for the commencement of this work of the Spirit in their souls. Morally and in substance, it corresponds to the ministry of John the Baptist and to that of the Lord Himself after John had been cast into prison. (See Matt. 3:2, 5-6; and ch. 4:17.)
Having been thus aroused by the action of the Spirit in their hearts and consciences then, a faithful remnant among them will begin to repent of their moral departure from Jehovah, their God. It will mark the beginning of a work in their souls, but that work will not reach its perfection until they see Christ coming "in His glory" (Matt. 25:31 and Zech. 12:10). More on this however in the next feast below.
Now as to the significance of this being the time of grape harvest, everywhere in the Scriptures, Israel is typified as Jehovah's vine. When He comes to claim the fruit that is rightfully His though, they bring forth only wild grapes. This is what happened when Messiah came to them the first time; but when He comes to them the next time, their hearts will be willing and He will once again drink of the fruit of the vine. In the meantime though and until then, His interests are elsewhere-that is, with His assembly. (See Psa. 80:8-11;110:3; Isa. 5:1-7; Matt. 21:33-9; and 26:29.)