Part 1

A few decades before Jesus was born, two rabbis, Hillel and Shammai, debated Deuteronomy 24. Hillel noted the text said a man could divorce his wife for "a cause of sexual immorality." Since rabbis believed that every word in Scripture was there for a reason, Hillel decided that this word "cause" must refer to other grounds for divorce besides sexual immorality. Hillel believed a man could leave his wife for any reason: wearing her hair unbound or burning the toast.

Shammai, on the other hand, thought that Deuteronmy 24 only referred to sexual immorality, and that this "any cause" divorce was wrong.

Hillel's "any cause" divorce was popular among Jewish men. It was much easier to get, though more expensive. It is almost certainly what Joseph was thinking of when he considered divorcing Mary "quietly" in Matthew 1:19.