Jewish law regarded an engaged couple as virtually married. Usually women married at about13or14years of age, [1] and their husbands were often several years older. Normally a one-year period of waiting followed the betrothal before the consummation of the marriage. During that year the couple could only break their engagement with a divorce. [source][source][source]
". . . a betrothed girl was a widow if her fiance died (Kethub. i2), and this whether the man had "taken" her into his house or not. After betrothal, therefore, but before marriage, the man was legally "husband" ..." [2][source]
Joseph, being a "righteous" (Gr. dikaios) Prayer of Manasseh , could hardly let his fiance"s pregnancy pass without action since it implied that she had been unfaithful and had violated the Mosaic Law. Joseph had three choices concerning how to proceed. First, he could expose Mary publicly as unfaithful. In this case she might suffer stoning, though that was rare in the first century. [3] Probably she would have suffered the shame of a public divorce ( Deuteronomy 22:23-24). A second option was to grant her a private divorce in which case Joseph needed only to hand her a written certificate in the presence of two witnesses (cf. Numbers 5:11-31). [4] His third option was to remain engaged and not divorce Mary, but this alternative appeared to Joseph to require him to break the Mosaic Law ( Leviticus 20:10). He decided to divorce her privately. This preserved his righteousness (i.e, his conformity to the Law) and allowed him to demonstrate compassion. [source][source][source]