Nehemiah 4:16-18

So it was, from that time on, that half of my servants worked at construction, while the other half held the spears, the shields, the bows, and wore armor; and the leaders were behind all the house of Judah. Those who built on the wall, and those who carried burdens, loaded themselves so that with one hand they worked at construction, and with the other held a weapon. Every one of the builders had his sword girded at his side as he built. And the one who sounded the trumpet was beside me.