Qitzur Shulchan Arukh – 182:1
סִימָן קפב – הִלְכוֹת גְּנֵבָה וּגְזֵלָה
182: Laws of Theft and Robbery
It is prohibited to steal or to rob even the slightest amount, whether from a Jew or a non-Jew. It is brought in the Tana deVei Eliyahu: A story involving one person who told me that he committed a trespass against a non-Jew when assessing the value of the figs that he sold him. Afterward he took all the money and bought oil, but the jug broke and the oil spilled. I said, “Blessed is the Omnipresent before Whom there is no favoritism. The verse says “do not defraud your neighbor and do not steal.
And stealing from a non-Jew is stealing.
This se’if goes to the core of why I decided to do this series of posts.
See also the discussion at se’if 62:7.