Rashi on Leviticus 25:47/רש"י על ויקרא כ״ה:מ״ז

1יד גר ותושב [AND IF] A גר ותושב WAX RICH — This means a stranger, he being at the same time a sojourner with thee, as the Targum renders it: ערל תותב an uncircumcised sojourner (the phrase is hendiadys). The end of the verse proves this, for it states: “and he sells himself unto a strange sojourner” (גר תושב, without the copulative ו before the second word).

2וכי תשיג יד גר ותושב עמך AND IF A STRANGE SOJOURNER WAX RICH BY THEE — The last word suggests: What was the cause that he has waxen rich? His close connection with thee (עמך) (Sifra, Behar, Chapter 8 1).

3ומך אחיך עמו AND THY BROTHER WAX POOR BY HIM — Here again the last word suggests: What was the cause that he has waxen poor? His intimacy with him (Sifra, Behar, Chapter 8 1), — because of the fact that he learned evil from his (the stranger’s) evil doings.

4משפחת גר — itself denotes a heathen; since, however, Scripture adds the word לעקר “to the stock of the heathen’s family” it thereby refers to one who sells himself to the idol itself — to be its servant; not to worship it as a deity, but e. g., to chop wood or to draw water which are to be used in connection with this idol worship (cf. Sifra, Behar, Chapter 8 1; Bava Kamma 113b; Arakhin 30b; Kiddushin 20a).