'Watchman's' in the Bible

His house has no more strength than a spider's thread, or a watchman's tent.

The daughter of Zion is left like a shelter in a vineyard,Like a watchman’s hut in a cucumber field, like a besieged city.

But if the watchman see the sword come, and blow not the trumpet, and the people be not warned; if the sword come, and take any person from among them, he is taken away in his iniquity; but his blood will I require at the watchman's hand.