One student had gone out. I guess he went to the washroom or something like that. So he came back and Patanjali was delighted. He embraced him and he taught him the whole grammar. But a goat, which was grazing there, why came along? And he saw these bundles of palm leaves and started chewing on them. That is called the Ajabhakshitabhasya, the goat eaten commentary. It's such a colorful and nice story that I wanted to tell you but that's grammar.
Swami Sarvapriyananda teaches the Mundaka Upanishad which one of the major Upanishads belonging to the Atharva Veda. Mundaka means ''shaved'' like a shaved head. The teachings revealed in this Upanishad are meant to leave the student clean, or shaved of the veil of ignorance. Indeed, the study of this Upanishad has been traditionally confined to the shaven-heads, or the sannyasins, who have renounced everything and devoted themselves exclusively to contemplation. The book consists of 64 Mantras (verses) split across Mundakas (parts) and Khandas (sections) as follows:
Mundaka 1 - Khanda 1 - 9 mantras (1.1.1 - 1.1.9)
Mundaka 1 - Khanda 2 - 13 mantras (1.2.1 - 1.2.13)
Mundaka 2 - Khanda 1 - 10 mantras (2.1.1 - 2.1.10)
Mundaka 2 - Khanda 2 - 11 mantras (2.2.1 - 2.2.11)
Mundaka 3 - Khanda 1 - 10 mantras (3.1.1 - 3.1.10)
Mundaka 3 - Khanda 2 - 11 mantras (3.2.1 - 3.2.11)
Reference books:
1. Mundaka Upanisad translated by Swami Gambhirananda - https://www.vedanta.com/store/mundaka-upanisad-with-the-commentary-of-sankaracarya_moreinfo.html (or)
2. Eight Upanisads Vol. 2 translated by Swami Gambhirananda - https://www.vedanta.com/store/Eight-Upanishads-Commentary-by-Shankara_moreinfo.html