Matthew 1:19

Then Joseph her husband, being a just man, and not willing to make her a publick example, was minded to put her away privily.

For the better apprehension of what is here said, it should be remembered, that it was the custom among the Jews to betroth, or make engagements for future marriages, before that any intention was formed of the time when the nuptials were to be consummated. sometimes those betrothings were made years before the parties came together Yea, Jewish parents sometimes contracted for their children, before, the young persons had any knowledge of, and much less a predilection for, each other. Hence, in case afterwards matters arose of difference, there was a law made for disannulling. See Deuteronomy 22:23, and Deuteronomy 24:1, etc. Such was the case of Joseph and Mary. They were but betrothed to each other, though Mary is here called His wife. So that the miraculous conception took place before that they came together. Joseph is here represented as deliberating how to act on the Occasion. And it must be confessed, that it affords an amiable picture of his mind.