וַיִּשְׁאַ֣ל יַעֲקֹ֗ב וַיֹּ֙אמֶר֙ הַגִּֽידָה־נָּ֣א שְׁמֶ֔ךָ וַיֹּ֕אמֶר לָ֥מָּה זֶּ֖ה תִּשְׁאַ֣ל לִשְׁמִ֑י וַיְבָ֥רֶךְ אֹת֖וֹ שָֽׁם׃
And Yaakov asked and said: Tell me, please, your name. And he said: Why is it that you ask for my name? And he blessed him there.
Torah Temimah points to Chullin 91b.
וישאל יעקב ויאמר הגידה נא שמך — א"ל: למה זה תשאל לשמי?
“And Yaakov asked and said: Tell me, please, your name.” He said to him: Why is it that you ask for my name?
The angel declines to reveal his name and proceeds to bless Yaakov.
Derash on the dialogue (Bavli).
The angel refused to disclose his name and instead gave Yaakov a blessing.