Another interpretation: "For you have striven with God" means: You are the one whose likeness is engraved on high. "And Jacob asked and said, Tell me, I pray, your name" (Genesis 32:30). One verse says, "He counts the number of the stars" (Psalms 147:4), and another verse says, "He brings out their host by number" (Isaiah 40:26). Rather, this teaches that there is a change there: an angel is not called now by the name by which it will be called later, as it is said (Judges 13:18), "And the angel of the LORD said to him, Why do you ask my name, seeing it is wondrous?" meaning, I do not know into which name I will be changed. (Genesis 32:32) (written at remez 105 and at remez 119).
Jacob's Image Engraved Above and the Angel's Shifting Name
Yalkut Shimoni on Torah 133:4
דָּבָר אַחֵר, כִּי שָׂרִיתָ עִם אֱלֹהִים, אַתְּ הוּא שֶׁאִיקוּנִין שֶׁלְּךָ חֲקוּקִין לְמַעְלָה. (בראשית לב ל) וַיִּשְׁאַל יַעֲקֹב וַיֹּאמֶר הַגִּידָה נָּא שְׁמֶךָ. כָּתוּב אֶחָד אוֹמֵר "מוֹנֶה מִסְפָּר לַכּוֹכָבִים" וְגוֹ' וְכָתוּב אֶחָד אוֹמֵר (ישעיה מ, כו) "הַמּוֹצִיא בְמִסְפָּר צְבָאָם" וְגוֹ, אֶלָּא מְלַמֵּד שֶׁיֵשׁ שָׁם שִׁנּוּי לֹא כְּשֶׁהוּא נִקְרָא עַכְשָׁו הוּא נִקְרָא לְאַחַר זְמַן, שֶׁנֶּאֱמַר (שופטים יג, יח) "וַיֹּאמֶר לוֹ מַלְאַךְ ה' לָמָּה זֶּה תִּשְׁאַל לִשְׁמִי וְהוּא פֶלִאי" אֵינִי יוֹדֵעַ מֵאֵיזֶה שֵׁם אֲנִי מִתְחַלֵּף. (בראשית לב לב) (כָּתוּב בְּרֶמֶז ק"ה וּבְרֶמֶז קיט).