This stranger - Often God receives more praise and affectionate obedience from those who had long lived without his knowledge and fear, than from those who were bred up among his people, and who profess to be called by his name. The simple reason is, Those who have Much forgiven will love much, Luke 7:47.

There are not found that returned,.... Or it do not appear, that any have returned:
to give glory to God; for inasmuch as they did not return to give thanks to Christ, and acknowledge him the author of their cure and cleansing they did not give glory to God:
save this stranger; for so the Samaritans were reckoned by the Jews, even as the Gentile, aliens from the commonwealth, of Israel, and strangers to the covenants of promise. Christ speaks in the language and dialect of the nation, and yet we find sometimes, that, "a Cuthite", or a Samaritan, is distinguished from, "a stranger", Or a Gentile: they might set up their beasts in the inns of the Samaritans, but not in the inns of "strangers"; and a man might let out his bath to a Samaritan, but not to a "stranger" (b); but this must be understood of them in times past, before they were found out to be idolaters; when, as Rabban Simeon ben Gamaliel says (c), they were as Israelites in all things, and kept the law and the precepts of it, and even more exactly than the Israelites themselves did (d); but afterwards a Samaritan was reckoned a Gentile, and so he was in the times of Christ; and therefore he calls a Samaritan a stranger: that tradition of the Jews, requires some notice and consideration (e); all are defiled
"with leprosies, except "strangers", and the proselyte of the gate.''
And yet here is a stranger among the Jews, and reckoned unclean, on account of leprosy, and sent with them to show himself to the priest.
(b) T. Bab. Avoda Zara, fol. 15. 2. & 21. 2. (c) T. Hieros Shekalim, fol. 46. 2. (d) Maimon. in Misn. Beracot, c. 8. sect. 8. & Bartenora in ib. c. 7. sect. 1. (e) Misn. Negaim, c. 3. sect. 1. Maimon. Tumaot Tzaraot, c. 9. sect. 1.

this stranger--"this alien" (literally, "of another race"). The language is that of wonder and admiration, as is expressly said of another exhibition of Gentile faith (Matthew 8:10).