“…You shall not make idols for yourselves…you shall keep my sabbaths…I am Hashem…” – Vayikra 26:1-2

לֹא תַעֲשׂוּ לָכֶם אֱלִילִם . . אֶת שַׁבְּתֹתַי תִּשְׁמֹרוּ . . אֲנִי ה’ – ויקרא כו, א-ב

The final verses of Parshas Behar caution us in the observance of a number of mitzvos stated previously in the Torah. Rashi explains that the Torah directs these warnings at the person discussed in the preceding verses—a Jew who has sold himself into slavery to a non-Jew. He might assume, says Rashi, “Since my master has illicit relations… worships idols… desecrates the Shabbos, I may also be like him.” The Torah therefore warns that despite his subjugation to a non-Jew, he must nevertheless observe the mitzvos. Theparsha then concludes, “I am Hashem,”—“Who is faithful to give reward” (Rashi); i.e., the slave’s devotion to the Torah despite his circumstances will not go unrewarded.

Though every person who observes the mitzvos elicits a divine response, the Torah makes special mention that G-d will reward the slave because the slave might suspect that in his current situation he is incapable of receiving divine compensation.

To explain:

Everything we have comes from G-d: our rains and our crops, our health and our livelihood. Still, the “G-dliness” of our blessings, i.e., the degree to which their divine source is revealed, varies.

During the Shemittah year, for example, when agricultural work in the Land of Israel is prohibited, the survival of the Jewish people living in Israel is distinctively and recognizably supernatural. Now, in truth, a Jew’s needs arealways provided for supernaturally—just as the Jewish nation has been miraculously preserved by G-d throughout history. But in the non-Shemittah years, when G-d instructs us, “Six years you shall sow your field, and six years you shall prune your vineyard,” our trulysupernatural blessings come to us through a natural vehicle—our physical toil and the workings of nature.

For a non-Jew, the garb of nature through which G-d provides is even more concealing. So much so, that a non-Jew is prone to believe that the forces of nature determine his sustenance and that they are not merely carrying out the will of G-d (see Devarim 4:19).

Since the Jewish slave of a non-Jew is dependent upon his gentile master for his sustenance, he might begin to assume that he, too, is (currently) incapable of receiving the divine reward for observing the Shabbos and refraining from idol-worship—rewards which certainly transcend any natural disguise whatsoever. The Torah therefore reiterates that G-d Himself—“who is faithful to give reward”—has given the commandments, and He can and will fully compensate all who observe the mitzvos, regardless of their current circumstances.

—Likutei Sichos, vol. 7, pp. 183-187