“When he arose, he took the young child and his mother by night, and departed into Egypt:”
Matthew 2:14 — Greek Interlinear
Church Fathers on Matthew 2:14
Here Matthew omits the day of purification when the first-born must be presented in the Temple with the lamb, or a pair of turtle doves, or pigeons. Their fear of Herod did not make them bold to transgress the Law, that they should not present the Child in the temple. As soon then as the rumour concerning the Child begins to be spread abroad, the Angel is sent to bid Joseph carry Him into Egypt.
by this that the Angel appears always to Joseph in sleep, is mystically signified that they who rest from mundane cares and secular pursuits, deserve angelic visitations.
The first time when he would teach Joseph that she was lawfully espoused, the Angel called the Virgin his espoused 'wife;' but after the birth she is only spoken of as the Mother of Jesus. As wedlock was rightfully imputed to her in her virginity, so virginity is esteemed venerable in her as the mother of Jesus.