There are four varnashramam of which Gruhasthashramam (House Holder) is much celebrated by Vedas and Maharishis. Athithi Satkaaram is sole right of a Gruhasthan and this is called as Virunthombal in Tamil. Taitriya Upanishads says “Athithi Devo Bhava” the athithi has to be treated with affection and hospitality as like doing service for Bhagavan. Swami Desikan in Abhaya Pradhaana Saaram mentions the importance and advantages of Athithi Satkaaram. This article talks about Virunthombal from the parable Vedanum Puravum in which a pigeon falls into the fire to give food to the hunter.
For similiar article on Athithi Satkaaram can be viewed here : Athithi Satkaaram