Katha-1-1-28-ajīryatāma

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

Again, having approached those whose age knows no decay and who are immortal and knowing of some other surpassing benefit to be had from them, how çould a mortal, himself living on earth below (below, relatively the Antariksha, i.e., region of the sky), pray for such transitory things, as sons, wealth, gold, etc., covetable only by the ignorant? Another reading has ‘Kvatadasthah’ for ‘Kvadhasthah’; the meaning according to this reading is this: Tadasthah, one who ardently covets them, i.e., sons and the rest; when will one, who seeks higher objects than these though difficult to attain, thirst for these? The meaning is that no one who knows them as valueless, will wish for them. Everybody in the world wishes to become something higher and higher than he is; therefore, I am not to be tempted by the prospect of sons, wealth, etc.; and what sensible man will delight in longevity who knows the transitory nature: of nymphs and of the delights of music and sports?

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