Nehemiah 4:18-20

18Every builder had his sword secured at his side as he built. And the one who sounded the trumpet [to summon the troops] stood at my side.

19I said to the nobles, the officials and the rest of the people, “The work is great and extensive, and we are separated on the wall, far from one another.

20Wherever you hear the sound of the trumpet, gather to us there. Our God will fight for us.”