Commentaire de citation sur Josué 9:18

Avimelech also wanted to deny the argument that they had caused Isaac's good fortune to be interrupted by their expulsion; this could not have been the case seeing that G'd had been its author. The fact that he was still better off today than when he resided amongst them was the proof; עתה ברוך ה', "now that they had already done all that was in their power with the means at their disposal, it was clear that he was blessed by the Lord" since he had found the real source of such blessing. All these arguments were designed to elicit an oath the legality of which would be unassailable under any circumstances. There is a discussion in Gittin 46 why the Jewish people did not make war against the Gibeonites when they found out that the latter had tricked them into a promise to treat them as allies instead of as Canaanites (Joshua 9,18). Rabbi Yehudah holds that since the oath was sworn by the leaders of the Jewish people, Israel could not take action denying the validity of that oath. The other rabbis disagree, claiming that the Israelites' undertaking was never valid as it had been based on the Gibeonites' declaration that they were a people who lived far from the land of Canaan. Clearly, Rabbi Yehudah was concerned with the image of Jewish leaders who by defaulting on an undertaking denigrate the reputation of G'd whom they represent. Rashi explains that Rabbi Yehudah's point is not that the oath was valid, but that the Gentiles must not be allowed to say that Jewish leaders were guilty of perjury. We must remember that Rabbi Yehudah's point is not a legal one, i.e. a Mosaic law, but an act of piety that Jewish leaders have to impose upon themselves. Besides, even according to Rabbi Yehudah, such a consideration is in place only when the oath was as public as that of the Jewish people to the Gibeonites. Oaths between a relatively small group of people such as Isaac and Avimelech's entourage would certainly not fall under that heading.