First, the kinds of relationships that qualify for marriage in the
Bible, and thus could count as "biblical marriage," represent quite a
striking range of options. They include polygyny (more than one wife or
concubine, simultaneously), open marriage for the man (since he can have
access to the female slaves or servants in the house), forcing a woman
to marry her rapist (Deuteronomy 22:28-29) and levirate marriage
(wherein a childless widow must marry the brother of her deceased
husband). Those are just a few of the examples from the Hebrew Bible.