St. Hilary of Poitiers ca. 300-368
She is called the Mother of Christ, because this she was; not the wife of Joseph, because this she was not. (Comment. In Matthaeum, I, 3; Graef, 55)
Thus the expression “He knew her after the birth” (cf. Mat. 1:25) means that Mary receives the title of wife. The text, then, asserts that he knew her, not that he was joined to her. (Comment. In Matthaeum, I, 3; Gambero, 184)
Now, if these were Mary’s sons, instead of children that Joseph had fathered during a previous marriage, then, at the moment of the Passion, Mary never would have been given the Apostle John as His mother, …For the Lord, to help her face her solitude, left her, in His disciple, the love of a son. (Comment. In Matthaeum, I, 4; Gambero, 185)