The Torah in Parashat Kedoshim (19:33) reiterates the prohibition against oppressing foreigners who come to join Am Yisrael: “If a foreigner lives with you in your land, do not oppress him…” Curiously, the Torah here speaks specifically of a foreigner who lives “be-artzekhem” (“in your land”), in the Land of Israel. Quite obviously, it is forbidden to oppress converts to Judaism anywhere in the world, and not merely in Eretz Yisrael. Why, then, would the Torah here specify the case of a convert who joins the nation in our land? (See Torat Kohanim, which explains this verse as indicating that different standards of proof are required in Eretz Yisrael and in other locations when somebody claims to have become a convert.)
Rav Pinchas Menachem Yustman (the Piltzer Rebbe), in Siftei Tzadik, suggests that the Torah specifies the situation of a convert in Eretz Yisrael because converts were not assigned portions in the land. When Benei Yisrael entered the land, the territory was divided among the families at that time, such that foreigners were not guaranteed a plot. This may have led some to the mistaken conclusion that they may mistreat converts, or at least deny them the same rights and privileges granted to other members of the nation. After all, they might assume, if the Torah denied them a guaranteed portion of Eretz Yisrael, then they must have a lowly status, and may therefore be treated as such. To dispel this dangerous misconception, the Torah here emphasizes that even in Eretz Yisrael all converts must be treated fairly, respectfully, and as full-fledged members of the nation.
The Tolna Rebbe of Jerusalem applied this insight of the Siftei Tzadik to all situations of people who seem to have been denied certain privileges by Providence. A person might look around him and notice many people who were not fortunate enough to have the same level of intelligence as his, to have received the same quality education he received, to have enjoyed the same kind of stable upbringing and happy childhood that he did, or to have the same financial success that he enjoys. The Siftei Tzadik’s comment reminds us that we must never feel superior to other people on account of talents, resources or other advantages and privileges that we have been given and they haven’t. It is not for us to know why God makes some people healthier, wealthier, more intelligent, more socially adept, or more skilled than others. The prohibition against oppressing a foreigner, when seen from this perspective, teaches us that we must give respect to all people, even to those whom we feel we have reason to view as inferior.