The Alter Rebbe explained at the conclusion of the previous chapter that through teshuvah ila’ah, the higher level of repentance, the soul is totally cleansed and purified. It then ascends and cleaves to G‑d with the same degree of unity that it enjoyed before it descended into the body. Furthermore, the Alter Rebbe quoted the Zohar to the effect that teshuvah ila’ah involves studying Torah with awe and love of G‑d.
In the fourth chapter, however, he explained that teshuvah ila’ah involves reinstating the higher letter hei of the Tetragrammaton. What possible connection does this have with studying Torah out of love and fear of G‑d, when these two spiritual emotions are related to the letter vav?
In order to resolve this seeming anomaly, the Alter Rebbe will now explain that the love and fear discussed in the present chapter are generated intellectually: they result from meditation upon G‑d’s greatness, and are thus the offspring of Binah. It is specifically this kind of love and fear that unites the hei and the vav — the intellect with the resulting emotions.