And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
All Commentaries on Matthew 1:25 Go To Matthew 1
John Chrysostom
AD 407
“Took unto him” not took home to him; for he had not sent her away; he had put her away in thought only, and now took her again in thought.
As one might say, ‘He told it not so long as he lived;’ would this imply that he told it after his death? Impossible. So it were credible that Joseph might have known her before the birth, while he was yet ignorant of the great mystery; but after that he understood how she had been made a temple of the Only-begotten of God, how could he occupy that? The followers of Eunomius think, as they have dared to assert this, that Joseph also dared to do it, just as the insane think all men equally mad with themselves.
It may be said, that “know” here signifies simply, to understand; that whereas before he had not understood how great her dignity, after the birth he then "knew” that she had been made more honourable and worthy than the whole world, who had carried in her womb Him whom the whole world could not contain.