To the sea - The Sea of Galilee, or to the lonely regions which surrounded the sea, where he might be in obscurity, and avoid their designs against his life. His time had not yet come, and he prudently took care of his life, thus showing that we are not needlessly to throw ourselves into danger.
Galilee - See the notes at Matthew 2:22.
Judea - The southern division of the land of Palestine.
Jerusalem - Jerusalem was "in" Judea. It is mentioned particularly to show that not only the people of the surrounding country came, but also many from the capital, the place of wealth, and honor, and power.
Idumea - The country formerly inhabited by the "Edomites." In the time of the Saviour it was embraced in the country belonging to the Jews. It was south of Judea proper. The word "Idumea" is a Greek word made from the Hebrew "Edom." It signifies the land of Edom, a name given to Esau, one of the sons of Isaac, Genesis 25:30. The word signifies "red," and the name was given to him because he sought of Jacob red pottage as the price of his birthright. He settled in Mount Seir Deuteronomy 2:5, on the south of the land of Canaan, and the country of Idumea was bounded by Palestine on the north. During the Babylonian captivity the Edomites spread themselves into the country of Judea, and occupied a considerable part of the south of Palestine. They had, however, submitted to the rite of circumcision, and were incorporated with the Jews. From them sprang Herod the Great.
From beyond Jordan - From the region lying east of the river Jordan. The sacred writers lived on the west side of Jordan, and by the country "beyond Jordan" they meant that on the east side.
Tyre and Sidon - See the notes at Matthew 11:21.

Galilee - See Matthew 4:13, Matthew 4:15.

But Jesus withdrew himself with his disciples to the sea,.... Knowing their evil designs against him, he departed out of the synagogue, and city of Capernaum; and taking his disciples with him, he went to the shore of the sea of Galilee; not out of fear, but because his time was not yet come, and he had more work to do:
and a great multitude from Galilee: from the several parts of it, in which country he now was:
and from Judea: that part of the land of Israel, which was particularly so called, and belonged to the tribe of Judah.

Jesus withdrew himself. See fuller notes on the popularity described in Luke 3:7-12 under Matthew 12:15-21.
The sea. Of Galilee. Also consult map for the localities named.