The fifth Lubavitcher Rebbe, Rabbi Sholom Dov Ber Schneerson (known as the Rebbe Rashab), was once traveling with his son, Rabbi Joseph Isaac, to Vienna, where they stayed in a hotel. When Rabbi Joseph Isaac entered his father’s room, he saw his father lying on the couch, with his eyes open, seemingly unaware of his surroundings. About an hour later, he entered again, and saw his father still lying there, motionless as before.

The Rebbe remained lying like that for several hours, lost in his thoughts and seemingly in another world.

When the Rebbe awoke from his state of deep contemplation, he was not aware of the date, and did not even remember where he was. His son, Rabbi Joseph Isaac, had to orient his father to time and place.

Later, the Rebbe explained to his son that on that day he had contemplated deep concepts in Chassidic thought. These ideas were later recorded in a book of Chassidic discourses, Sefer Maamorim 5672.

In his great devotion to G-d, the Rebbe reached a state of being “cut off” from the physical world, to the point of being unaware of what was going on around him. This state is referred to in Chassidic thought as “klot hanefesh”—when the soul, in its yearning to cleave to G-d, separates itself from the physical body.

In this week’s Torah portion, we read of the two sons of Aaron, Nadav and Avihu, who died after bringing “a strange fire before the L-rd.” When the Tabernacle was erected, Nadav and Avihu were so eager to perform the service that they brought a pan of incense and entered the Sanctuary to offer it on the altar. However, since G-d had not commanded them to do this, they both perished.

Chassidic teachings explain that Nadav and Avihu likewise experienced klot hanefesh—their souls expired out of their intense longing to be close to G-d.

A story is told of the Modzitzer Rebbe, Rabbi Yisrael Taub, a renowned composer of Chassidic melodies, niggunim. He had to undergo a serious operation to amputate a gangrenous foot. However, the doctors were worried about his ability to withstand the surgery, since his heart was very weak. No anesthesia was available at that time.

When he heard this, the Rebbe asked them to wait to begin the surgery until he sang a Chassidic tune. While he was deep into the melody, the doctors performed the surgery and he did not feel a thing. The spiritual feelings that he poured into the niggun made him oblivious to his physical body.

The ultimate goal, however, is not to reach a state that the soul leaves the body. Rather, it is to take that inspiration and return to earth, to carry out the soul’s mission here below. The Modzitzer Rebbe went on to live a number of healthy years in which he led and guided his many chassidim; the Rebbe Rashab recorded his Chassidic insights in books which are studied by thousands.