Katha-1-1-8-āśāpratīkṣe

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

Hope, i.e., wish for something not definitely known but attainable. Expectation, looking out for something definitely known and attainable. Company with good men, i.e., the fruit resulting from association with good men. Sweet discourse, i.e., the fruit of true and pleasant speech. Ishtam, i.e., the fruit of a sacrifice. Púrtam, i.e., the fruit resulting from charities such as the laying out of a garden, etc. Putrapasûn, i.e., children and cattle. All this is destroyed of the men with little intelligence in whose house, a Brahman, fasting stays. The meaning is that a guest is, therefore, under no circumstances to be neglected.

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