The seven chambers of the upper worlds - First chamber: Yesod
The Zohar explains that the preceding seven compartments are the building blocks and foundation for another, still higher level of chambers.
The realm of Yesod is the domain of the angel who dispenses great mercy to all those souls who convert and follow the true path of The Creator.
55. Rabbi Shimon said, Come and behold: These seven compartments OF THE UPPER WORLDS, about which we have spoken, contain seven chambers based on the secrets of Faith, WHICH IS MALCHUT OF THE WORLD OF ATZILUT. These correspond to the seven firmaments. In each and every chamber there are supernal spirits, WHO ARE THE ANGELS RESPONSIBLE FOR THOSE CHAMBERS. The first chamber, WHEN COUNTING FROM BELOW, IS CALLED YESOD AND has a spirit who is in charge of the souls of the converted. His name is Rachmiel, BECAUSE HE EXTENDS MERCY (HEB. RACHAMIM) TO THOSE SOULS. Through him, they delight in the radiance of divine glory.
55. תָּא חֲזֵי אָמַר רָבִּי שִׁמְעוֹן ז' מָדוֹרִין אִינוּן דְּקָאֲמָרָן, וּבְגוֹ אִינוּן אִית ז' הֵיכָלִין, מֵאִינוּן רָזֵי מְהֵימְנוּתָא, לָקֳבֵל ז' רְקִיעִין עִלָּאִין, וּבְכָל הֵיכָלָא וְהֵיכָלָא אִית רוּחִין עִלָּאִין. הֵיכָלָא קַדְמָאָה: הָכָא אִית רוּחָא, דְּאִתְמַנּוּ עַל נִשְׁמַתְהוֹן דְּגֵרִין דְּאִתְגַיְירוּ, וְרָחְמִיאֵ"ל שְׁמֵיהּ, וְאִיהוּ נָטֵיל לוֹן וְאִתְהַנּוּן מִזִּיו יְקָרָא דִלְעֵילָא.