וּבְנֵ֨י יַעֲקֹ֜ב בָּ֤אוּ מִן־הַשָּׂדֶה֙ כְּשָׁמְעָ֔ם וַיִּֽתְעַצְּבוּ֙ הָֽאֲנָשִׁ֔ים וַיִּ֥חַר לָהֶ֖ם מְאֹ֑ד כִּֽי־נְבָלָ֞ה עָשָׂ֣ה בְיִשְׂרָאֵ֗ל לִשְׁכַּב֙ אֶת־בַּֽת־יַעֲקֹ֔ב וְכֵ֖ן לֹ֥א יֵעָשֶֽׂה׃
雅各的兒子們一聽見這事,就從田野回來。他們心裡憂傷,非常憤怒,因為他在以色列中做了醜事,與雅各的女兒同寢;這樣的事是不應當做的。
Rashi
וכן לא יעשה AND THUS IT OUGHT NOT TO BE DONE — viz., to do violence to a maiden, for even the heathens have trained themselves (literally, have fenced themselves round) against unchastity as a consequence of the Flood which had come upon the world as a punishment for this sin (Genesis Rabbah 80:6).
Ramban
AND THUS IT OUGHT NOT TO BE DONE. I.e., to do violence to maidens, for the nations “had fenced themselves round” against unchastity as a result of the Flood. This is Rashi’s language. But I do not know this, for the Canaanites were immersed in unchastity with women, beasts and males, as it is written, For all these abominations have the men of the land done, that were before you,128Leviticus 18:27. and they did not begin such practices in that generation [but rather it was their traditional behavior], and even in the days of Abraham and Isaac, the patriarchs feared lest they kill them in order to take their wives. Instead, the expression, and thus it ought not to be done, refers back to the word beyisrael (in Israel): because he had wrought a vile deed in Israel… and thus it ought not to be done among them. This is why Scripture said in Israel for it was not a base deed among the Canaanites. And Onkelos translated: “It is not proper that it be done,” meaning that it is forbidden, and that is why it was a base deed in Israel.
Rashbam
ובני יעקב באו מן השדה, during this time Chamor had come from the town to speak to Yaakov, finding the brothers present.