Joel 2:15

15 Blow the trumpet [a] in Zion, hallow a fast, proclaim a solemn assembly;

Joel 2:15 Meaning and Commentary

Joel 2:15

Blow the trumpet in Zion
For the calling of the people together to religious duties, which was one use of the silver trumpets made for and blows by the priests, ( Numbers 10:2 Numbers 10:3 Numbers 10:8 Numbers 10:10 ) ; sanctify a fast, call a solemn assembly; (See Gill on Joel 1:14).

Joel 2:15 In-Context

13 and rend your heart, and not your garments, and turn unto Jehovah your God: for he is gracious and merciful, slow to anger, and of great loving-kindness, and repenteth him of the evil.
14 Who knoweth? He might return and repent, and leave a blessing behind him, an oblation and a drink-offering for Jehovah your God?
15 Blow the trumpet in Zion, hallow a fast, proclaim a solemn assembly;
16 gather the people, hallow the congregation, assemble the elders, gather the children, and those that suck the breasts; let the bridegroom go forth from his chamber, and the bride from her closet.
17 Let the priests, the ministers of Jehovah, weep between the porch and the altar, and let them say, Spare, O Jehovah, thy people, and give not thine inheritance to reproach, that they should be a byword of the nations. Wherefore should they say among the peoples, Where is their God?

Footnotes 1

The Darby Translation is in the public domain.