Wyjścia 18:9 Komentarz: Rashi, Chizkuni, Da'at Zekenim & Sforno

ויחד יתרו AND JETHRO REJOICED — This is its literal meaning. A Midrashic comment is: his flesh became full of prickles (חדודין — his flesh crept with horror) — he felt grieved at the destruction of Egypt. That is what people say (what the common proverb says): A proselyte even though his heathen descent dates from as far back as the tenth generation, do not speak slightingly of an Aramean (any non-Jew) in his presence (Sanhedrin 94a).

ויחד יתרו, “Yitro rejoiced;” we find this root meaning the same in Psalms 21,7: תחדהו בשמחה, “You gladdened him with the joy (of Your presence)” [A reference to the Messiah having been gladdened. Ed.] [I have not understood what follows concerning the comparison with Numbers 21,1 and Job 31,27. Ed.] Rashi on this verse brought the talmudic saying: “That is what people say (what the common proverb says): A proselyte even though his heathen descent dates from as far back as the tenth generation, do not speak slightingly of an Aramean (any non-Jew) in his presence (Sanhedrin 94a).” There are some (Hadar Zekenim) who say that this is because Ishmael son of Netanya that was a tenth generation descendant to an Egyptian convert, and he had made the Egyptians revenge on Israel.

ויחד יתרו, according to Rashi, the word ויחד means that Yitro’s flesh broke out in goose-pimples when reflecting on what had happened to Pharaoh and his army. Rashi’s grandson, Rabbeinu Tam, pointed out that Rashi had scriptural proof to support this interpretation. We find the following verse in Chronicles I, 2,35: ויתן ששן את בתו לירחע עבדו לאשה, “Sheshan gave his daughter to his (Egyptian slave) as a wife.” [This Egyptian slave had of course converted before being given a Jewish wife. Ed.] If you count from the word ירחע until the word אלישמע in the verses following the above until verse 41 you will get to Yishmael ben Netanya ben Elishama that there were 13 generations. Deduct 3 generations when Egyptians are not allowed to convert to Judaism and you will find confirmation for the opinion quoted by Rashi, that a convert’s genes do not completely disappear for 10 generations until there is not a trace of his original character that surfaces on occasion. Rashi, quoting a Mechilta, had warned that in the presence of a convert we must not speak in derogatory terms about a gentile unless being certain that the Jew to whom we speak who had had pagan ancestry, was already at least the descendant of nine previous Jewish generations. Yitro, a first generation convert, clearly would feel discomfort when reflecting on the fate that had befallen Pharaoh.