Vadim,
You wrote
"I do think that 'verb lo l'isha' etymologically means something like
concubine, or property-wise lighter than marriage."
Just to make sure that I understand you. You believe that Sarah was not Abram's wife (Gen. 20:12), nor was Rebekah Isaac's wife (Genesis 24:67), nor was Rachel Jacob's wife (Gen. 29:28), nor was Jochebed Amram's wife (Ex. 6:20), etc.
Does the Scripture name a wife for any of these men?
I don't believe that the Scripture ever calls Leah Jacob's wife? What was her
relationship to Jacob?
Sincerely,
Michael Abernathy