Likutei Moharan 78:3/ליקוטי מוהר"ן ע״ח:ג׳

13. This is also the concept of ruach hakodesh (holy spirit). Human life depends on the ability to breathe. What is breathing? It is exhaling and inhaling air (ruach), as in “The living creatures ran and returned” (Ezekiel 1:14). Therefore, when a person is attached to the Malkhut of Holiness and speaks words of Torah or prayer, he exhales and inhales the ruach (air) of holiness. This is the meaning of “I will put a new spirit into you” (ibid. 36:26)—i.e., in your insides. When a person breathes a breath of holiness, then “I will put a new ruach (spirit)”—namely, ruach hakodesh .

2And this is the meaning of “and the spirit of God hovering over the water’s surface” (Genesis 1:2). This is when one studies Torah, for water connotes Torah, as is known. Then “the ruach of God,” which is ruach hakodesh, is “hovering” and extending over it, and he draws ruach (breath) of life. For without Torah it is impossible to live, as it is written, “If not for the lobes of the lungs fanning the heart, the heart would consume the entire body” (Tikkuney Zohar #13, p.28a). The lungs are associated with water (Zohar III, Raaya Mehemna, p .218b), and water connotes Torah.

3When a Jew’s heart burns for God, this [fiery passion] could consume him completely. But <when he is enclothed> in the letters of Torah or prayer, they protect and save him. The reverse, God forbid, is likewise so. When a person burns with desire for the temptations of this world, this, too, would consume his entire body <were it not that he draws life and sustenance from the Other Side>. But afterwards, <if he occupies himself with Torah, prayer and mitzvot, they protect and save> him. He can then live, because he draws ruach (breath) of life, which is ruach hakodesh, from the attribute of Malkhut, his source.

4This is the reason the wicked are considered dead even while alive (Berakhot 18b). They have been severed from the rope of holiness. From where are they to acquire life? Instead, they draw a spirit of foolishness, because they are attached to “an old and foolish king” (Ecclesiastes 4:13). <For> a person does not sin unless a ruach of foolishness enters him (Sotah 3a). Whereas if it is the other way around, ruach hakodesh enters him.

5Ruach hakodesh is the aspect of Malkhut, as Scripture states: “Esther donned malkhut (kingship)” (Esther 5:1)—and our Sages, of blessed memory, expounded: she donned ruach hakodesh (Megillah 15a) .