एकरात्रं तु निवसन्नतिथिर्ब्राह्मणः स्मृतः ।
अनित्यं हि स्थितो यस्मात् तस्मादतिथिरुच्यते ॥
A Brāhmaṇa staying for a single night and whose date of coming is not fixed, he has been declared to be a “guest” (Atithi). Because his stay is not long, therefore he is called “Atithi”
– Manu Smriti 3.102
