Nehemiah 4:16-18

16From that day on, half of my servants carried on the work while the other half held the spears, shields, bows, and breastplates; and the captains were behind the whole house of Judah.

17Those who were rebuilding the wall and those who carried burdens loaded themselves so that everyone worked with one hand and held a weapon with the other.

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.