7 The word of God says in Genesis, “And they gave unto Jacob all the strange gods which were in their hand, and the rings which were in their ears; and Jacob hid them under the oak which was by Shechem, and lost them until this day.” Likewise at the end of Deuteronomy, “So Moses the servant of the Lord died there in the land of Moab, according to the word of the Lord. And he buried him in the valley, in the land of Moab over against Beth-peor: but no man knows of his sepulchre unto this day.”
We must certainly understand by this day the time of the composition of the history, whether you prefer the view that Moses was the author of the Pentateuch or that Ezra re-edited it. In either case I make no objection. The question now is whether the words unto this day are to be referred to the time of publishing or writing the books, and if so it is for him to show, now that so many years have rolled away since that day, that either the idols hidden beneath the oak have been found, or the grave of Moses discovered; for he obstinately maintains that what does not happen so long as the point of time indicated by until and unto has not been attained, begins to be when that point has been reached.
He would do well to pay heed to the idiom of Holy Scripture, and understand with us, (it was here he stuck in the mud) that some things which might seem ambiguous if not expressed are plainly intimated, while others are left to the exercise of our intellect. For if, while the event was still fresh in memory and men were living who had seen Moses, it was possible for his grave to be unknown, much more may this be the case after the lapse of so many ages. And in the same way must we interpret what we are told concerning Joseph.
The Evangelist pointed out a circumstance which might have given rise to some scandal, namely, that Mary was not known by her husband until she was delivered, and he did so that we might be the more certain that she from whom Joseph refrained while there was room to doubt the import of the vision was not known after her delivery.
Source: The Perpetual Virginity of Blessed Mary (New Advent)