'Wall' in the Bible

“My beloved is like a gazelle or a young stag.Behold, he is standing behind our wall,He is looking through the windows,He is peering through the lattice.

“If she is a wall,We will build on her a battlement of silver;But if she is a door,We will barricade her with planks of cedar.”

“I was a wall, and my breasts were like towers;Then I became in his eyes as one who finds peace.