At that time God will thresh from the River Euphrates to the Brook of Egypt, and you, people of Israel, will be selected grain by grain. At that same time a great trumpet will be blown, calling home the exiles from Assyria, Welcoming home the refugees from Egypt to come and worship God
on the holy mountain, Jerusalem.
Isaiah 27:12-13 The Message Bible

Day 14 – 40 Days of the Shofar
Blow the trumpet in Zion and sound the alarm. The 9th of Av is a special day on God's calendar. It's part of the appointed times of the Fall Feasts. Many things have happened historically on this date.