זוהר, האדרא זוטא כ׳Zohar, Idra Zuta 20

Segment 1א׳

וְהַאי אָב וָאֵם וּבֵן, אִקְרוּן חָכְמָה בִּינָה וָדַעַת. בְּגִין דְּהַאי בֵּן נָטִיל סִימָנִין דַּאֲבוֹי וְאִמֵּיהּ, אִקְרֵי דַּעַת, דְּהוּא סַהֲדוּתָא דְּתַרְוַויְיהוּ. וְהַאי בֵּן, אִקְרֵי בּוּכְרָא. דִּכְתִּיב, (שמות ד׳:כ״ב) בְּנִי בְכוֹרִי יִשְׂרָאֵל. וּבְגִין דְּאִקְרֵי בּוּכְרָא, נָטִיל תְּרֵין חוּלָקִין. וְכַד אִתְרַבֵּי בְּעִטְרוֹי, נָטִיל תְּלַת חוּלָקִין. וּבֵין כַּךְ וּבֵין כַּךְ, תְּרֵין חוּלָקִין, וּתְלַת חוּלָקִין כֹּלָּא חַד מִלָּה. וְהַאי וְהַאי הֲכִי (ס"א חד) הֲוֵי, יְרוּתָא דְּאָבוֹי וְאִמֵּיהּ יָרִית.

And these, Father and Mother and son, are called chochmah, binah and da'at (knowledge). Because this son takes the marks of his Father and Mother, he is called da'at, for he is the testimony of both of them. And this son is called the firstborn, as it is written, “Israel is My son, My firstborn” (Ex. 4, 22). And because he is called the firstborn, he takes two portions; and when he grows great in his crowns, he takes three portions. And either way, two portions and three portions are all one thing. And this and this are so (a variant reads: one): he inherits the inheritance of his Father and Mother.