'Fenced' in the Bible

Now Jericho [a fortified city with high walls] was tightly closed because [of the people’s fear] of the sons of Israel; no one went out or came in.

And David said to Abishai [his nephew], “Now Sheba the son of Bichri will do us more harm than Absalom did. Take your lord’s servants and pursue him, so that he does not find fortified cities for himself and escape from our sight.”

You shall strike every fortified city and every choice (principal) city, and cut down every good tree and stop up all sources of water, and ruin every good piece of land with stones.’”

Against every high tower,Against every fortified wall,

‘Call to Me and I will answer you, and tell you [and even show you] great and mighty things, [things which have been confined and hidden], which you do not know and understand and cannot distinguish.’