what does the bible say?
Prenuptial agreements in the Bible are reflected in the concept of a bride price, known as mohar, which was paid by the groom to the bride's father or male relative (Genesis 34:12; Exodus 22:16; 1 Samuel 18:25). This payment served as financial security for the bride, especially in a patriarchal society where women lacked property rights and depended on their husbands or sons for support (Numbers 27:1–11). The bride price also acted as a form of alimony, intended to ensure the bride's welfare in case of divorce or the husband's death, emphasizing the importance of financial arrangements in ancient marriage (Exodus 22:16–17).
Often, young men were not able to afford the entire mohar at the time of the wedding. Rabbis then included the promise of a future mohar into the ketubah—the prenuptial agreement explaining the husband's responsibility to the wife both during the marriage and, if need be, upon their divorce. The prenuptial agreement we know today derived from the same idea. A woman who married devoted her life to supporting and promoting her husband's professional success. Like the women in Bible times, she probably didn't have a significant source of income for herself, nor had she taken the steps to be competitive in the job market. A prenuptial agreement would ensure she was supported should her husband divorce her, as well as acknowledge the part she played in her husband's success.
As idealistic as it is to say that the Bible rejects prenuptial agreements, it simply isn't true. God is a realist and intensely concerned with the rights and protection of the vulnerable. As long as a prenuptial agreement is used to protect and support the innocent, it cannot be said to be unbiblical.