Rabbi Yochanan said: Were it not for the letter vav in the word "heeluukha" ["who brought you up," plural] in the verse (Exodus 32:4), the enemies of Israel [a euphemism for Israel itself] would have been liable to utter destruction. Rabbi Shimon ben Yochai said to him: But surely anyone who joins the name of Heaven together with something else is uprooted from the world, as it is said, "except to the LORD alone" (Exodus 22:19). Rather, what does Scripture come to teach by saying "who brought you up" [in the plural]? That they craved many deities.
The Vav of Heelukha That Spared Israel From Destruction
Yalkut Shimoni on Torah 348:3
אֲמַר רַבִּי יוֹחָנָן, אִלְמָלֵא וָי"ו (שמות לב, ד) שֶׁבְּ"הֶעֱלוּךָ" נִתְחַיְּבוּ שׂוֹנְאֵיהֶן שֶׁל יִשְׂרָאֵל כְּלָיָה. אֲמַר (לֵיהּ) רַבִּי שִׁמְעוֹן בֶּן יוֹחַאי, וַהֲלֹא כָּל הַמְּשַׁתֵּף שֵׁם שָׁמַיִם וְדָבָר אַחֵר נֶעֱקַר מִן הָעוֹלָם, שֶׁנֶּאֱמַר בִּלְתִּי לַה' לְבַדּוֹ, אֶלָּא מַה תַּלְמוּד לוֹמַר "אֲשֶׁר הֶעֱלוּךָ", שֶׁאִוּוּ לֶאֱלָהוּת הַרְבֵּה.