'Guard' in the Bible

Then David came to his house at Jerusalem, and the king took the ten women, the concubines whom he had left to keep the house, and placed them under guard and provided them with sustenance, but did not go in to them. So they were shut up until the day of their death, living as widows.

But Amasa was not on guard against the sword which was in Joab’s hand so he struck him in the belly with it and poured out his inward parts on the ground, and did not strike him again, and he died. Then Joab and Abishai his brother pursued Sheba the son of Bichri.

He was honored among the thirty, but he did not attain to the three. And David appointed him over his guard.