What can you know about the comparable word "bi"?

I think, just think about it, "Shuo Wen Jie Zi" says: Bi, from female. Let's start from the right. If it's the upper part of the royal palace, it's a cage. The woman who lives in the palace is a concubine. These concubines are not comparable to ordinary women, so they are comparable. This is my own understanding, hehe.