But, those who are fit for worldly existence, they are living in the midst of ignorance, as though in the midst of thick darkness, being entangled in hundred of fetters, forged by craving for sons, cattle, etc.; considering – (thinking of themselves) “we ourselves are intelligent and versed in the scriptures” – those senseless, non-discriminating people go round and round by following very much the various crooked courses, being afflicted by old age, diseases, etc.; just as many blind people , being led by the blind, indeed, on an uneven road, come to great calamity.
Because of this alone, because of ignorance, the means for the attainment of the other world does not become revealed (to them):
Samparayah is the other world attainable after the falling of the body; any particular scriptural means leading to the attainment of that other world does not become revealed, does not become serviceable to a boy, a non-discriminating man… who is confounded, being covered in darknes (of ignorance) because of the non-discrimination caused by wealth. “There is only this world – that which is visible and abounds with women, food, drink; there is no other world, that is invisible”; constantly thinking thus, (he) gettting born, again and again, becomes subject to the control of me, who am Death; that is, he remains involved in a succession of grief in the form of birth, death. Such is the world in general. But among thousands, it is only one like you who hankers after the preferable, and who becomes a knower of the Self… (Katha Upanishad Bashia, I.ii.5-6)
Yama (Death), son of the Sun and imparter of the knowledge of Brahman (ultimate reality)