Part 13 · Chapter 30

And Arich Anpin is a name that includes the two heads, namely Keter and Mocha Stima'ah, which are the two heads below the RDL"A. And every head must be included of ten, and therefore they divide into two discernments: each of the two has in it the aspect of ten Sefirot, for in Keter there are ten Sefirot, and likewise in the concealed Hochma, called a real head.