The Power of Simcha:
Sefer M’Zekeinim Esbonen quotes Rav Mordechai Chaim of Slonim zy”a as asking why Esav had to wait for his father to die. Esav was a rasha and a murderer. Why didn’t he just kill Yaakov now?
He answers that Esav could not harm Yaakov as long as he was happy. The Baal Shem Tov zy”a said that when someone is happy, nothing can hurt him and no one can do him any harm. As long as Yitzchok was alive, Yaakov was in a constant state of happiness, therefore, Esav was waiting for his father to die. He thought that Yaakov would be sad during the days of mourning, and he would then finally be able to kill him.
וַיֹּאמֶר עֵשָׂו בְּלִבּוֹ יִקְרְ בוּ יְמֵי אֵבֶל אָבִי וְאַהַרְ גָה אֶת יַעֲקֹב וגו' (כז, מא)
And Esav said in his heart, “The days of mourning for my father will draw near. I will then kill my brother Yaakov.” (27:41)
