וַיִּשְׁלַח מֹשֶׁה מַלְאָכִים וְגוֹ' כֹּה אָמַר אָחִיךָ יִשְׂרָאֵל.... אַתָּה יָדַעְתָּ, כְּשֶׁאָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא לְאַבְרָהָם, יָדֹעַ תֵּדַע כִּי גֵּר יִהְיֶה זַרְעֲךָ (בראשית טו, יג), אָנוּ נִשְׁתַּעְבַּדְנוּ, וְאַתָּה בֶּן חוֹרִין.
וְיָרְדוּ אֲבוֹתֵינוּ וְכָל אוֹתוֹ הָעִנְיָן. מָשָׁל לְמַה הַדָּבָר דּוֹמֶה. לִשְׁנֵי אַחִים שֶׁיָּצָא שְׁטַר חוֹב עַל זִקְנֵיהֶם, פָּרַע אוֹתוֹ אֶחָד מֵהֶם. לְיָמִים הִתְחִיל לִשְׁאֹל חֵפֶץ מֵאָחִיו. אָמַר לוֹ: אַתָּה יוֹדֵעַ שֶׁאוֹתוֹ חוֹב שֶׁפָּרַעְתִּי, עַל שְׁנֵינוּ הָיָה, וַאֲנִי הוּא שֶׁפְּרַעְתִּיו, לְכָךְ אַל תַּחְזִירֵנִי מִן חֶפְצִי שֶׁאֲנִי שׁוֹאֵל.
“Then Moses sent messengers... ‘Thus says your brother Israel…. You know all the hardships that have befallen us.’” They said to him, “You know when the Holy One, blessed be G-d, said to Abraham [Gen. 15:13], ‘know full well that your seed shall be strangers [in a land not theirs where they shall serve them and be oppressed by them],’ it was we who were enslaved, while you are free.”
“How our forefathers went down to Egypt....” This whole subject is comparable to two brothers against whose grandfather a promissory note appeared. One of them arose and paid it. One day he started to ask a favor from his brother, and he said to him, “You know that debt was incumbent on both of us, but it was I who paid it. Do not refuse any of my favor that I am asking” (Num. 20:15).
אתה ידעת את כל התלאה. היו ישראל מפתים אותם בדברים כאדם שמספר לפני אהבו וקרובו תלאותיו ומספר לו מאורעיו לפי שישים אל לבו וירחם עליו:
“You know all the hardships....” Israel was appealing to [Edom] with these words, as a person might appeal to their loved one or family member, about their hardships, and recounting the events in order to touch [Edom's] heart and cause them to have compassion on [Israel].
ואומרו אתה ידעת פירוש כבר קודם היות לנו התלאה ידעת אותה שנגזרה בין הבתרים, ודבר זה דוקא הוא שידעו, ולזה דקדק לומר אתה, העובדי כוכבים ומזלות היו חושבים כי מקרה הירידה היה להם להיות עבדים ושפלים.
And they said “You know [all the hardships]....” [Moses] expanded on the hardship in order to remind [Edom] that they knew about what had been decreed “between the parts” [Gen. 15:13, that Abraham's descendants were to be enslaved], and this thing indeed only they knew, which is why he specified "you." The [other] idol-worshippers considered the Israelites' being enslaved and despised [in Egypt] an unfortunate accident that happened to them because they migrated there.
...Moses' peaceful response to Edom, made conspicuous by his armed victories in the other cases, recalls Genesis and another earlier episode in Jacob's story. Edom is Esau, the older brother whom Jacob supplanted in the matter of the blessing and birthright and who planned to kill him (Gen. 27:41-42). Later, when the brothers meet, Jacob is afraid because Esau comes out in force; Jacob concedes to Esau's show of arms by sending gifts, the brothers embrace, Esau forgives Jacob the old wrong and they part with exchange of gifts (Gen. 33:1-16). So when Moses greets Edom with a message from 'your brother Israel,' when he humbly accepts Edom's rebuff, when he concedes to Edom by going round his territory, he is re-enacting the patriarch's encounter with his brother.
(8) You shall not abhor an Edomite, for he is your kinsman. You shall not abhor an Egyptian, for you were a stranger in his land.
“You shall not abhor an Edomite.” Completely, although it would be proper for you to abhor him because he came out against you with the sword (Num. 20:18-20).
לא תתעב אדומי.... אע"פ שהיה לך לתעבו לפי שלא הניחך לעבור דרך ארצו לא תתעבנו כי אחיך הוא:
“You shall not abhor an Edomite.” .... Even though you might have abhorred them because they did not allow you to pass through their territory, you must not abhor [the Edomite] because he is your brother.
Israel is prohibited from nurturing grievances against the Edomites: Do not abhor an Edomite, for he is your kinsman. But even more fundamentally, it is forbidden from becoming hard-hearted as a result of its often harrowing past. The people's encounter with Edom on its way to the land of promise is intended as a warning and an awakening: when you are settled in your land, people who are hungry and exhausted may come looking for help. Treat them not as you yourselves were treated, but as you would have wanted to be treated. It would be all too easy for the past to teach you brutality; let it teach you kindness instead.