Likutei Moharan 52:5/ליקוטי מוהר"ן נ״ב:ה׳

15. Here you have leshon Rabbeinu z’l of this lesson, which he composed with extreme brevity:

2Who goes on his way alone. He who stays awake at night…

3Know, the essence of bitul—that a person negates his corporeality and becomes ayin (nothingness), becoming encompassed in the oneness of God—is achieved only through hitbodedut .

4Now the hitbodedut requires a special place and time so that he is not disturbed by distractions. The time is at night—i.e., He who stays awake at night—for then everyone is asleep. The place is on a secluded road, and not a public road, so that he is not interrupted by people passing by. Rather, it should be specifically a road not frequently travelled—he should go there and seclude himself. This is: Who goes on his way alone. Then he will be able to empty his heart of all <dross and waste>, and be able to attain a bitul of all <his> corporeality <and become naught and nothing>. This is: and makes room in his heart for batalah. And then, when he is entirely transparent, he is encompassed in the oneness of God. He then attains the aspect of mechuyav (“necessary”), for the Holy One is a necessary reality, whereas all things are a contingent reality. Thus when a person is transparent and is encompassed in His oneness, he then leaves the aspect of contingent <reality> and is encompassed in meChuYaV <reality>. And this is the aspect of he is mitChaYeV his own soul .