When a person learns Torah, he closes a circuit.
As he thinks of and says the words of Torah, he connects this world to the transcendent divine beyond this world.
In this unification between the holiness revealed in the world in Torah and mitzvot and the divine Being beyond the world, the Shekhinah rests on a person's divine soul.
–Rabbi Adin Steinsaltz
From Understanding the Tanya, Chapter 35, by Rabbi Adin Steinsaltz