It is written, “if you cry after knowledge (Binah), and lift up your voice for understanding (Tevunah)” (Mishlei 2:3). He asks, once he says, “you cry after Binah,” why follow with, “lift up your voice for Tevunah”? He answers, everything is as I said. When Binah nourishes the son and the daughter, it is called Tevunah (as in section 83).
He asks, which one is higher, and answers, Binah is higher than Tevunah. Binah is father and mother and son, as Yud-Hei are a father and a mother with a son between them, who is Vav. Meaning, Binah is spelled with the letters of ben (son of) Yud-Hei. Tevunah in all comprises the children; Tevunah is spelled with the letters comprising ben (son) bat (daughter) Vav-Hei, but Yud-Hei do not appear in it.
We understand from this that Binah is higher than Tevunah, as father and mother, who are Yud-Hei, appear in Binah alone. But Yud-Hei are not part of the spelling in Tevunah; for Tevunah is the six directions of Binah. Surely, Ima is sitting over the young, who are Vav-Hei; but Ima herself is not seen there. Therefore, the letters for ben and bat Vav-Hei are present in the spelling of Tevunah, but Yud-Hei are not.
Thus, the children, Zeir Anpin and Malchut, as a whole are called Tevunah; and the father and mother and son, who are Chochmah, Binah and Zeir Anpin, as a whole are called Binah. And when seeking to include everything, that is, Yud-Hei as well, they are incorporated in Binah. Thus, when Zeir Anpin envelopes Israel Saba and Tevunah he has but the six directions; when he envelopes Aba and Ima he has Yud-Hei, the first three Sfirot.