Purva Mimamsa Sutras
The Mimamsa Sutra (Sanskrit: मीमांसा सूत्र, Mīmāṁsā Sūtra) or the Purva Mimamsa Sutras (ca. 300–200 BCE), written by Rishi Jaimini is one of the most important ancient Hindu philosophical texts. It forms the basis of Mimamsa, the earliest of the six orthodox schools (darshanas) of Indian philosophy. According to tradition, sage Jaimini was one of the disciples of sage Veda Vyasa, the author of the Mahabharata.
The work is divided into twelve adhyayas (chapters), which are further divided into sixty padas (sections).
The text provides rules for the interpretation of the Vedas and also provides philosophical justifications for the observance of Vedic rituals, by offering meaning and significance of Vedic rituals to attain Moksha.
Over the centuries many commentaries were written on this text, most important being the Śabara Bhāṣya written by Śābara, the only extant commentary on all the 12 chapters of the Mimamsa Sutras of Jaimini.  The major commentaries written on the text as well as the Śabara Bhāṣya were by Kumarila Bhatta and Prabhakara Mishra.
Jaimini, in his Mimamsa Sutra, presents material activity and its results as the whole of reality (vipanam rtam). He and later proponents of Karma-mimamsa philosophy teach that material existence is endless, that there is no liberation. For Mimamsas, the cycle of karma is perpetual, and the best one can aim for is higher birth among the Devas. Therefore, they hold that the whole purpose of the Vedas is to engage human beings in rituals for creating good karma, and consequently the mature soul's prime responsibility is to ascertain the exact meaning of the Vedas' sacrificial injunctions and to execute them.
Codana-laksano 'rtho dharmah: "Duty is that which is indicated by the injunctions of the Vedas."(Mimamsa Sutra 1.1.2)