EXOD283 The Talmud (Sanhedrin 84a) prohibits speaking in a derogatory manner about non-Jews while in the presence of a convert. Concerning [this verse] Rashi explains that the word "vayichad" [rejoiced] is related to the word "chidudin" -- prickles, meaning that Yisro's flesh became full of prickles, implying Yisro's anguish and resentment over the destruction of Mitzrayim. This is the intention of the popular expression, "Do not degrade a non-Jew while in the presence of a convert" (Sanhedrin 94a).