The Mīmāṁsā (also called Pūrva-mīmāṁsā) system of Hindu philosophy lays great emphasis on the performance of the rituals—which alone constitute the ‘dharma’—prescribed in the Vedas. The whole of the Vedas can be broadly divided into ‘vidhi’ or injunctions and ‘arthavāda’ or laudatory statements.
The vidhis again are classified into three groups:
The apūrva-vidhi (translated as ‘original injunction’) is a vidhi or injunction which has not been known previously (apūrva = unprecedented) To illustrate: In the Darśapūrṇamāsa sacrifice, there is the injunction, ‘vrīhīn prokṣati’ (‘He sprinkles the rice grains’). In the absence of this injunction the sprinkling with regard to the rice grains used in this sacrifice would never be known. But with this injunction, sprinkling of the rice grains becomes compulsory. Hence it is an original injunction.