Katha-2-2-1-puramekādaśa

Sri Shankara’s Commentary (Bhashya) translated by S. Sitarama Sastri

As Brahman is not easily knowable, this if commenced for the purpose of ascertaining the entity of the Brahman, again by another method. City] being like a city, this body is called a city, because we find in it the appendages of a city such as gatekeepers, their controllers, etc.; a city with all its appendages has been found to exist, for an owner independent of it and not mixed up with it; similarly, from its resemblance to a city, the body, a bundle of many appendages, must exist for an owner occupying the place of a king and not mixed up with it; and this city named body has eleven gates; seven in the head, and three lower down including the navel and one at the top of the head; whose this is, i.e., of the unborn] of the âtman not subject to modifications such as birth, etc., occupying the place of the king and dissimilar in its properties to the city; avakra chêtasah: whose chetah, i.e., knowledge is not crooked and eternally existent like the splendour of the sun and uniform, i.e., of the Brahman occupying the place of the king; contemplating on that Paramêsvara, highest Lord, the owner of the city; for the word anushthânam here means the contemplation of him leading to sound knowledge or realisation of him contemplating on him, as living equally in all things, one does not grieve, being freed from all desire; fearlessness being attained by knowing him, there being no occasion for grief, whence could he fear? Even here, he becomes freed from the ties of desire and karma induced by ignorance and being thus freed, he becomes free, i.e., does not enter a body again.

Links
Various resources on the Kathopanishad
Upanishad Series – Katopanishad Commentary by Swami Chinmayananda