Isaac's Light Blessing of Esau and the Yoke That Can Be Broken

(Proverbs 26:25): "When he makes his voice gracious, do not trust him, for seven abominations are in his heart." What is the meaning of "for seven abominations are in his heart"? Rabbi Yochanan said: It teaches that the Divine Presence answered Isaac and said to him, 'It is revealed and known before Me that he is destined to destroy the Temple and to enslave the twelve tribes.' At that moment he blessed him with a light blessing. He said to him (Genesis 27:40): "And by your sword you shall live, and your brother you shall serve" - when? As long as they sit and occupy themselves with Torah. But if they are negligent in the words of Torah - "you shall break his yoke from off your neck." Immediately (Genesis 27:22): "and the hands are the hands of Esau" - if they are worthy, "the voice is the voice of Jacob," and if not, "the hands are the hands of Esau."