Then Joseph her husband, being a just man, and not willing to make her a public example, decided to put her away privately.
All Commentaries on Matthew 1:19 Go To Matthew 1
Theophylact of Ochrid
The law decreed that the adulteress be pilloried, that is, exposed and punished publicly. How, then, was Joseph righteous since he intended to cover up her sin and thus to transgress the law? The answer is, first, that he was righteous for intending to do this very thing. He did not wish to be harsh, but in his great goodness took compassion on her, showing himself to be above the law, and already living in a manner superior to the decrees of the law. Secondly, since he himself knew that she had conceived of the Holy Spirit, he did not wish to pillory and abuse her who had conceived not by adultery but of the Holy Spirit. Behold what the evangelist says: "She was found to be with child." Found by whom? By Joseph; that is, he discerned that she had conceived of the Holy Spirit. Therefore he "was minded to divorce her secretly," for he no longer dared to take as a wife her who had been deemed worthy of such grace.