Can concubinage be a hijab in ancient times?

Because the rules of marrying and concubinage in ancient times were different.

The etiquette of concubinage in ancient times was to sit in a small sedan chair and enter the man's house from a side door. No wedding ceremony, little dowry, generally no dowry. After the establishment of monogamy, only the combination of the two sexes that conforms to the wedding etiquette is considered as legal husband and wife.

Marrying a wife is very formal, and it requires matching, divination and matchmaker's words. The bride price given by the man and the bride price given by the woman are both very generous, and they want to marry in ten miles.