Nyaya - Kaundinya.

कौण्डिन्यन्यायः

This maxim has its origin in the following story. There was a Brahman named Kaundinya. On the occasion of a feast in which many Brahmans were invited, curdled milk was served cut to all except Kaundinya for whom ghol (a species of that milk) was provided for. It is used to denote ?Exception proves the rule."