The sons of Jacob came upon the slain
That is, the rest of them, as the Targum of Jonathan paraphrases it; understanding what their two brothers had done, they came and joined them, and partook of stripping the slain of their clothes, or from them what they found of any worth about them:
and spoiled the city;
plundered it of all its goods and substance, spoiled all the inhabitants of it of their wealth:
because they had defiled their sister;
one of them had done it, which is imputed to them all, they not restraining him from it, when it was in their power; and perhaps approving of it, and made a laugh of and jest at it; or however did not punish him for it.