Musar for Kiddushin 60:8

The reason Jacob had to be called Israel is to teach us that he had a dual task. First he had to remove the influence of evil. We should not think that tricking Esau was unethical; on the contrary, it was part of the process of neutralizing spiritually negative influences. Next, as Israel, his task was to help positive spiritual forces to assert themselves, and for him personally to achieve ever closer affinity to G–d. The name Jacob was never discarded, not even after he was given the name Israel. The reason for this is that even the name ישראל contains elements of the name יעקב. We have demonstrated that the עקב part equals the number 172, the number of words in the Ten Commandments, whereas the letter י before is the link to them. We have also pointed out that Jacob's function as יעקב is the principle of היום לעשותם, whereas the function of ישראל is the מחר לקבל שכרם, receiving the reward for the מצות in the Celestial Spheres as alluded to in the name ישראל. The name יעקב contains numerous allusions to a variety of moral imperatives, some of which we have already mentioned. When Isaac said to Jacob, in his blessing: הוה גביר לאחיך, "be your brother's superior" (27,29), this was a command to subjugate the אדומי, the evil urge represented by Esau. Jacob was to do this in his capacity of יעקב. This is analogous to the Mishnah in Avot 4,1 we quoted earlier.