Charles Ellicott Commentary Mark 3:7-8

"And Jesus with his disciples withdrew to the sea: and a great multitude from Galilee followed; and from Judaea, and from Jerusalem, and from Idumaea, and beyond the Jordan, and about Tyre and Sidon, a great multitude, hearing what great things he did, came unto him." — Mark 3:7-8 (ASV)

And from Judea. ... and from Jerusalem.—The fact thus recorded is interesting as it implies, to some degree, the ministry in Jerusalem and its neighborhood, which the first three Gospels, for some reason or other, pass over.

From Idumea.—This is the only passage in the New Testament in which this country is named. It had acquired a considerably wider range than the Edom of the Old Testament and included the whole country between the Arabah and the Mediterranean. It was at this time under the government of Aretas (2 Corinthians 11:32), the father of the wife whom Herod Antipas had divorced, and this had probably brought about more frequent interaction between its inhabitants and those of Galilee and Perea.

They about Tyre and Sidon.—The fact is interesting in its connection with the history of the Syrophoenician woman (Matthew 15:21; Mark 7:24) as showing how it was that our Lord’s appearance in that region was welcomed as that of one whose fame had traveled there before Him.