'Fenced' in the Bible

And David said to Abishai, Now shall Sheba the son of Bichri do us more harm than did Absalom: take thou thy lord's servants, and pursue after him, lest he get him fenced cities, and escape us.

But the man that shall touch them must be fenced with iron and the staff of a spear; and they shall be utterly burned with fire in the same place.