Part 11 · Chapter 46

And now there are found six phases, and of them the VAK were made for ZA, and the Malchut was there at the end of the lower joint of the Hod, the seventh to him. Hence the Malchut in this phase is called the seventh. And now these seven phases were included, each one of them in all the seven, in the manner of what is said concerning the twenty-one mentions [of the Name] in the tefillin: since their root is only three, included in three, they are three times seven, which are twenty-one, for only the three were revealed, see there. Thus another correction was now added: at first he was three and she was the fourth to him, and now he is six and she is the seventh to him.