In the early years of his leadership, the founder of Chabad Chassidism, Rabbi Schneur Zalman of Liadi, would expound his teachings in the form of short homiletic sayings. It was only in later years (particularly after his liberation from imprisonment in Petersburg in 1798) that he began delivering the lengthy, intellectually profound discourses which characterize the "Chabad" system of Chassidic thought.

One of these early short discourses was based on the Talmudic passage, "All bearers of collars go out with a collar and are drawn by a collar" (Shabbat 51b). The Talmud is discussing the laws of Shabbat, on which it is forbidden for a Jew to allow his animal to carry anything out from a private domain to a public domain; however, it is permitted to allow one's animal to go out with its collar around its neck, and even to draw it along by means of its collar. But the Hebrew word the Talmud uses for "collar," shir, also means "song." Thus Rabbi Schneur Zalman interpreted the Talmud's words to say that, "The masters of song — the souls and the angels — go out in song and are drawn by song. Their 'going out' in yearning for G‑d, and their drawing back into their own existence in order to fulfill the purpose of their creation, are by means of song and melody."

This was in the early years of the Chassidic movement, when the opposition to Chassidism by many mainstream rabbis and scholars was still quite strong. This latest teaching by Rabbi Schneur Zalman, which quickly spread among his followers throughout White Russia and Lithuania, elicited a strong reaction from his opponents, who complained that the Chassidim have, yet again, employed homiletic wordplay and outright distortion of the holy Torah to support innovations to Jewish tradition. The Talmud, said they, is talking about collars worn by animals, not about the singing of souls and angels! No genuine Torah scholar could endorse, much less propagate, such an "interpretation."

Rabbi Schneur Zalman's words caused a particular uproar in the city of Shklov. Shklov was a town full of Torah scholars and a bastion of opposition to Chassidism. There were Chassidim in Shklov, but they were a small and much persecuted minority, and this latest controversy inflamed the ardor of their detractors. While the Chassidim of Shklov did not doubt the truth of their Rebbe's words, they were hard-pressed to defend them in the face of the outrage and ridicule this latest saying had evoked.

A while later, Rabbi Schneur Zalman passed through Shklov on one of his journeys. Among those who visited the Rebbe at his lodgings were many of the town's greatest scholars, who presented to him the questions and difficulties they had accumulated in the course of their studies. For even the Rebbe's most vehement opponents acknowledged his genius and greatness in Torah. The Rebbe listened attentively to all the questions put to him but did not reply to any of them. However, when the scholars of Shklov invited him to lecture in the central study hall, the Rebbe accepted the invitation.

When Rabbi Schneur Zalman ascended the podium at the central study hall of Shklov, the large room was filled to overflowing. Virtually all the town's scholars were there. Some had come to hear the Rebbe speak, but most were there for what was to follow the lecture, when the town's scholars would have the opportunity to present their questions to the visiting lecturer. All had heard of Rabbi Schneur Zalman's strange behavior earlier that day, when all the questions put to him were met with silence. Many hoped to humiliate the Chassidic leader by publicly demonstrating his inability to answer their questions. In the background, of course, loomed the recent controversy over the Rebbe's unconventional interpretation of the Talmudic passage about animals' collars on Shabbat.

Rabbi Schneur Zalman began to speak. "All those of shir," he quoted, "go out with shir and are drawn by shir." "The masters of song," explained the Rebbe, "the souls and the angels, all go out in song and are drawn by song. Their yearning for G‑d, and their drawing back to fulfill the purpose of their creation, are by means of song and melody." And then the Rebbe began to sing.

The room fell utterly silent. All were caught in the thrall of the melody, a melody of yearning and resolve, of ascent and retreat. As the Rebbe sang, every man in the room felt himself transported from the crowded hall to the innermost recesses of his own mind, where a man is alone with the confusion of his thoughts, alone with his questions and doubts. Only the confusion was gradually being dispelled, the doubts resolved. By the time the Rebbe finished singing, all the questions in the room had been answered.

Among those present in the Shklov study hall that day was one of the town's foremost prodigies, Rabbi Yosef Kolbo. Many years later, Rabbi Yosef related his experience to the Chassid, Reb Avraham Sheines. "I came to the study hall that day with four extremely difficult questions — questions I had put forth to the leading scholars of Vilna and Slutzk, to no avail. When the Rebbe began to sing, the knots in my mind began to unravel, the concepts began to crystallize and fall into place. One by one, my questions fell away. When the Rebbe finished singing, everything was clear. I felt like a newly-born child beholding the world for the very first time.

"That was also the day I became a Chassid," concluded Rabbi Yosef.