Mundaka-2-2-3-dhanur

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

Com.—How that is hit is now explained. Dhanuh. the bow. Grihitva, having taken. Upanishadam horn in, i.e., well-known in the Upanishads. Mahastram, great weapon, i.e., the arrow; fix the arrow; of what quality is stated. Upasauisltam, rendered pointed by constant meditation, i.e., purified; after fixing it and drawing it, i.e., having drawn the mind and the senses from their external objects and bending, i.e., concentrating them on the mark, for the bow here cannot be bent as by the hand; hit the mark—the immortal Brahman—above defined with thy mind, Oh good looking youth, engrossed by meditation upon the Brahman.

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