Rabbi Mordechai Yosef of Izhbitzeh (d. 1854)

Rabbi Mordechai Yosef of Izhbitzeh says that even in the technical laws of preparing food on Shabbos, Chazal hinted at the oaths. The Torah forbids cooking on Shabbos, and Chazal enacted the precaution of not even insulating cooked food on Friday with a substance that adds heat: "We may not insulate with olive pulp, manure, salt, plaster, or sand…we may insulate with clothing, fruit, the wings of a dove, sawdust or fine flax dust" (Mishnah Shabbos Ch. 4). We may insulate our life-force during exile so that it should not burn out, but we may not do anything that "adds heat" – to stir ourselves up to the point where we want to leave exile by force and push to the End, as the Gemara (Kesubos 111a) says that Hashem made us swear not to do this. "We may insulate with clothing" – the tzitzis, which protect us – "fruit" – the Four Species of the lulav – "the wings of a dove" – tefillin and mezuzos, as explained in the Gemara (Shabbos 49a) – "sawdust" – afflictions which bring atonement (from the similarity of the words "yisurin" and "nesores") and "fine flax dust" – acts of kindness. All these mitzvos protect us during exile, but we may not add heat and leave on our own, only when Hashem Yisborach shines His light upon us. (Mei Hashiloach on Shabbos, Ch. 4.)