The Gate of the Body of Arich Anpin and of Atik Yomin

And it is called the Gate of the Body of Arich Anpin and of Atik Yomin [Ancient of Days] (וְהוּא נִקְרָא שַׁעַר גּוּפוֹ שֶׁל אֲרִיךְ וְשֶׁל עַתִּיק יוֹמַיָּא), namely the body of the Malkhut of Adam Kadmon (דְּהַיְינוּ גּוּפוֹ שֶׁל מַלְכוּת אָדָם קַדְמוֹן), and Arich Anpin with the Reisha DeEin [Head of Nothingness] are joined together, one within the other (וַאֲרִיךְ עִם אֵין מְחֻבָּרִים יַחַד זוֹ בְּתוֹךְ זוֹ).