Augustine of Hippo
Catena Aurea · Lukasevangelium 2
And Joseph and his mother marvelled at those things which were spoken of him. And Simeon blessed them, and said unto Mary his mother, Behold, this child is set for the fall and rising again of many in Israel; and for a sign which shall be spoken against; (Yea, a sword shall pierce through thy own soul also,) that the thoughts of many hearts may be revealed.
(de Nov. ac vet, Test. c. 73.) Or by this is signified that Mary also, through whom was performed the mystery of the incarnation, looked with doubt and astonishment at the death of her Lord, seeing the Son of God so humbled as to come down even to death. And as a sword passing close by a man causes fear, though it does not strike him; so doubt also causes sorrow, yet does not kill; for it is not fastened to the mind, but passes through it as through a shadow.