John Chrysostom — as excerpted in the Catena Aurea on John 4:1-6

“(Hom. xxxi. 2) Christ on withdrawing from Judæa, joined those whom He was with before, as we read next, And departed again into Galilee. As the Apostles, when they were expelled by the Jews, went to the Gentiles, so Christ goes to the Samaritans. But, to deprive the Jews of all excuse, He does not go to stay there, but only takes it on His road, as the Evangelist implies by saying, And he must needs go through Samaria. Samaria receives its name from Somer, a mountain there, so called from the name of a former possessor of it. The inhabitants of the country were formerly not Samaritans, but Israelites. But in process of time they fell under God’s wrath, and the king of Assyria transplanted them to Babylon and Media; placing Gentiles from various parts in Samaria in their room. God however, to shew that it was not for want of power on His part that He delivered up the Jews, but for the sins of the people themselves, sent lions to afflict the barbarians. This was told the king, and he sent a priest to instruct them in God’s law. But not even then did they wholly cease from their iniquity, but only half changed. For in process of time they turned to idols again, though they still worshipped God, calling themselves after the mountain, Samaritans.”