Codana is very special to the Mimamsa system. It is a textual injunction in Vedas that inspires one to do a particular action. Any fruitful action laid down in Vedas is termed as dharma.
Vedas also contains a body of a sacred mantras which lay down certain rules as to how to perform various actions for attainment of various fruits which cannot be known from any other means of valid knowledge like perception, inference etc.
If one takes up a sentence from Vedas, svargokamo yajeta – meaning one who desires heaven should perform a sacrifice, it contains a verb yajeta. This verb too has two distinct parts – the root yajna (sacrifice) ad a suffix ta. This suffix ta has two properties in it. Firstly, its character as a verb and secondly in the state of operative mood. Among these the former is common to all the ten tenses and moods. The operative mood denotes a verbal urge in a person’s inclination.
Both these characters of the suffix ‘ta’ have three characteristics called what, through what and how. These, when answered, give a meaning thus: One should attain heaven by a sacrifice with various actions like getting fire, grains, rice, priests etc.
The three characteristics of the verbal urge will give the meaning as follows – one must have an urge to attain heaven, through the study of Vedas and by the knowledge of the eulogies and negations contained in the various portions of the same. These two characteristics are technically known as arthi bhavana and sabdi bhavana. With the two bhavanas the verb and the suffix give the full codana, the injunction, which propels the individual totally to attain his wish.