Rabbi Levi Yitzchak of Berditchev teaches that the wrestling encounter elevated even the angel of Esav, as Yaakov's holy power transformed the dark forces into a vessel for divine light. The name Yisrael thus represents Israel's capacity to uplift and transform the entire cosmos.
וירא כי לא יכול לו ויגע בכף ירכו (בראשית לב, כו). הענין, כמו שיש ג' עולמות עולם השרפים ועולם הגלגלים ועולם התחתון כן יש באדם הראש הוא נגד עולם השרפים שעל ידו משיג הבורא ברוך הוא והלב הוא נגד עולם הגלגלים וכן כתוב בספר יצירה לב ונפש גלגל בשנה שבבינת הלב יכול להשיג הבורא ברוך הוא מחמת תנועת הגלגלים והירכים שבאדם נגד עולם התחתון, היינו שעובד את הבורא ברוך הוא על ידי האמונה וזה מורה על הרגלים מלשון הרגל. וזהו הרמז ויגע בכף ירכו, שהעובד על ידי האמונה יוכל חס ושלום לבלבל. וזהו ויזרח לו השמש, שהתחיל לעבוד הבורא ברוך הוא בשכל ולזה שעובד בשכל אינו יכול לבלבל אותו. וזהו הרמז ויאמר לא יעקב, כי יעקב מורה על עבודה התחתונה יו"ד עקב כי אם ישראל שמורה על עבודה עליונה לי ראש: ויאמר לא יעקב יאמר עוד שמך כי אם ישראל כי שרית עם אלהים ואנשים ותוכל (בראשית לב, כט). הענין, כי יש אדם שהוא דבוק תמיד בהבורא ברוך הוא אפילו כשהוא מדבר עם בני אדם ויש אדם שהוא דבוק בהבורא ברוך הוא בעת שעוסק בעבודתו ובתורתו ובמצותיו אבל כשמדבר עם בני אדם אינו יכול לדבק מחשבתו להבורא ברוך הוא והבחינה הא' נקרא ישראל, כי הוא אותיות ישר אל וגם לי ראש והבחינה הב' נקרא יעקב יו"ד עקב. וזהו לא יעקב וכו', כי אם ישראל כי שרית עם אלהים, כלומר שאתה דבוק באלהים אפילו כשאתה מדבר עם בני אדם וזהו עם אלהים ואנשים, ותוכל לדבק מחשבתך תמיד להבורא יתברך:
Genesis 32,25. “when he realized that he could not overcome him he injured his hip joint.” The subjects alluded to here are the three parts of the universe, 1) the world of the disembodied spirits, angels, collectively known as שרפים 2) the inert “stars,” planets and galaxies in outer space, and 3) the living creatures in our own “lower” part of the universe. In our part of the universe, i.e. in man, the head represents the domain of the angels in the “upper” part of the universe, the part of man that enables him to recognize his Creator. The heart (within man) symbolizes the region we call outer space, home to galaxies in the domain known as עולם הגלגלים, the world of the orbiting planets and galaxies. According to the Sefer Yetzirah, heart, soul, enable man to recognise the recurring seasons, and what makes up a year by observing them in motion and realizing that a Creator must have directed their orbits. Finally, the thighs of man ירכים, represent the “lower universe,” a domain in which G’d must be served by means of His creatures having faith in their Creator. ירכים, thighs, are viewed as tools by means of which man is able to recognize the presence and power of a Creator. ירכים is another word for רגלים, which does not only mean “legs,” but is related to הרגל, habit, the danger that man serves G’d only from rote, lip service. When Yaakov is described as “the sun was shining for him”, ויזרח לו השמש, this is a hint that from that point on Yaakov worshipped G’d also by means of his intellect. His faith henceforth was more or less secure against arguments by the evil urge that could have confused him in his faith. The word י-עקב, was an allusion to his serving G’d as an עקב, an appendix, similar to the heel; once he had the name ישראל added to his name, he had acquired the letters ראש, (head) as part of his name, signifying the far loftier spiritual plateau that formed the basis of his faith. Genesis 32,28. “He said: ‘your name will no longer be Yaakov, but Israel, for you have contended both with celestial forces and with human forces and you have prevailed.’” There are people who constantly remain attached to G’d even while they are engaged in conversation with human beings. There are other people, who while engaged in a conscious effort to serve the Lord, concentrate on this to the exclusion of everything else; these people while engaged in mundane activities, such as business conversations with their peers, cannot at the same time remain conscious of their duties towards their Creator. The first type of person deserves the title: “Israel;” as the letters ישר, “upright,” as well as the letters ראש, “head,” are part of that title. The second category of person, (observant Jew) is called יעקב, i.e. י-עקב, meaning that his attachment to G’d is עקב, “secondary,” just as a heel is a secondary and not a primary organ. Esau’s celestial representative acknowledged that Yaakov was a person for the first category, since in his dealings with man he never lost sight of his primary duties to his G’d.