Charles Ellicott Commentary Matthew 2:13

"Now when they were departed, behold, an angel of the Lord appeareth to Joseph in a dream, saying, Arise and take the young child and his mother, and flee into Egypt, and be thou there until I tell thee: for Herod will seek the young child to destroy him." — Matthew 2:13 (ASV)

The angel—It is better translated as an angel. The interval of time between the departure of the Magi and Joseph’s dream is not specified, but it was probably very short. As with the Magi, the dream may have come as an echo of his waking thoughts—an answer to the perplexities with which their visit and the other wonders of the time had filled his spirit.

Flee into Egypt—The nearness of Egypt had always made it a natural asylum for refugees from Palestine. For example, Jeroboam found shelter there (1 Kings 11:40), and at a later date, Johanan the son of Kareah and his companions fled there from Nebuchadnezzar (Jeremiah 43:7). The number of Jews settled in Alexandria and other cities of Egypt probably made this move even more common during the tyranny of Herod’s later years.