प्रकरणात् ॥ ६ ॥
prakaraṇāt || 6 ||
6. On account of the subject-matter.
The Upanishad begins with, “What is that” (Mu. 1. 1. 4) and concludes by saying, “The knower of Brahman becomes Brahman” (Mu. 3. 2. 9), which shows that the subject-matter of the whole Upanishad from beginning to end is Brahman, and therefore it is the same Brahman which is spoken of as the abode of heaven etc.