Ambrose of Milan
Catena Aurea · Lukasevangelium 2
And it came pass, as the angels were gone away from them into heaven, the shepherds said one to another, Let us now go even unto Bethlehem, and see this thing which is come to pass, which the Lord hath made known unto us. And they came with haste, and found Mary and Joseph, and the babe lying in a manger. And when they had seen it, they made known abroad the saying which was told them concerning this child. And all they that heard it wondered at those things which were told them by the shepherds. But Mary kept all these things, and pondered them in her heart. And the shepherds returned, glorifying and praising God for all the things that they had heard and seen, as it was told unto them.
Esteem not the words of the shepherds as mean and despicable. For from the shepherds Mary increases her faith, as it follows: Mary kept all these sayings, and pondered them in her heart. Let us learn the chastity of the sacred Virgin in all things, who no less chaste in her words than in her body, gathered up in her heart the materials of faith.