John Lightfoot on Mark 5:1

[Into the country of the Gadarenes.] So also Luke: But Matthew, into the country of the Gergesenes. And, which ought not to be passed over without observation, Mark and Luke, who call it the country of the Gadarenes, make mention only of one possessed person; but Matthew, who calls it the country of the Gergesenes, speaks of two. We know what is here said by commentators to reconcile the evangelists. We fetch their reconciliation from the very distinction of the words which the evangelists use, and that from those conclusions:

I. We say the region of the Gergesenes was of broader extent and signification than the region of the Gadarenes was, and that the region of the Gadarenes was included within it. For whether it were called so from the old Gergashite family of the Canaanites, or from the muddy and clayey nature of the soil, which was called Gergishta by the Jews, which we rather believe; it was of wider extension than the country of the Gadarenes; which denoted only one city, and the smaller country about it, and that belonged to Gadara. But this country comprehended within it the country of Gadara, of Hippo, and of Magdala, if not others also.

II. We say Gadara was a city of heathens, (hence it is less marvel if there were swine among them) which we prove also elsewhere, when we treat of the region of Decapolis.

III. We say there were two possessed persons according to Matthew, one a Gadarene, another coming from some other place than the country of Gadara, namely, from some place in the country of the Gergesenes.

IV. We believe that that Gadarene was a heathen; and that Mark and Luke mentioned only him on set purpose, that so they might make the story the more famous. Any one skilled in the chorography of the land of Israel might understand that the country of the Gadarenes was of heathen possession: they therefore mark him with that name, that it might presently be perceived that Christ now had to do with a heathen possessed person; which was somewhat rare, and except the daughter of the Syrophoenician woman, without any example. Matthew would describe the greatness of the miracle; he therefore mentions two most miserably possessed persons: but Mark and Luke choose out only one, and him more remarkable for this very thing, that he was a Gadarene, and by consequence a heathen. These things, well weighed, do not only confirm the concord between the evangelists, but render the story far clearer. For,

First, It is to be marked that the devil adjures Christ not to "torment" him, verse 7, which is not elsewhere done by him: as though he were without Christ's jurisdiction among the heathens. And,

Secondly, Christ does not elsewhere ask any about their name, besides this alone, as being of more singular example and story.

Thirdly, The heathen name legion, argues him a heathen concerning whom the story is.

Fourthly, The devils besought him much that he would not send them out of the country; for being among heathens, they thought they were among their own.

Our Saviour, therefore, healed those two in Matthew together, the one, a Gadarene and heathen, and the other from some other place, a Gergesene and a Jew; and that not without a mystery; namely, that there should be comfort in Christ both to Jews and Gentiles, against the power and tyranny of Satan. Of those two, Mark and Luke mention the more remarkable.