אָמַ֗רְתִּי אֶֽשְׁמְרָ֣ה דְרָכַי֮ מֵחֲט֪וֹא בִלְשׁ֫וֹנִ֥י אֶשְׁמְרָ֥ה לְפִ֥י מַחְס֑וֹם בְּעֹ֖ד רָשָׁ֣ע לְנֶגְדִּֽי׃
Ich sprach: Ich will meinen Wandel hüten, nicht zu sündigen mit meiner Zunge; ich will hüten meinen Mund mit einem Schloss, während der Frevler mir vor Augen ist.
Idra Zuta
You may wonder, who is Atika Kadisha? That is, who is included under the name Atika Kadisha? He answers, come and see, in the highest heights there is that which is unknown, incomprehensible and unmarked; this is the unknowable head. It is all inclusive, and the two lower heads – the skull and the concealed brain, which are right and left – are incorporated in it; that is, it unites them. Everything was established this way, that is, as two heads to right and left and one to include and unite them. And that unknowable head is not counted among the Sfirot, nor is it part of them, that is, it is not even a Keter to them. Nor is it enumerated, for it is not of the aspect of Binah called calculus, but it is in the wish of the heart. Hence it says, “I said, I will take heed to my ways, that I sin not with my tongue” (Tehillim 39:2).