Definition: lit. the great commentary. The word is uniformly used by commentators and classical Sanskrit writers for the reputed commentary on Pāṇini's Sūtras and the Vārttikas thereon by Patañjali in the 2nd century B. C. The commentary is very scholarly yet very simple in style, and exhaustive although omitting a number of Pāṇini's rules. It is the first and oldest existing commentary on the Aṣṭādhyāyī of Pāṇini, and, in spite of some other commentaries and glosses and other compendia, written later on to explain the Sutras of Panini, it has remained supremely authoritative and furnishes the last and final word in all places of doubt: cf. the remarks इति भाष्ये स्थितम्, इत्युक्तं भाष्ये, इत्युक्तमाकरे etc. scattered here and there in several Vyaakarana treatises forming in fact, the patent words used by commentators when they finish any chain of arguments. Besides commenting on the Sutras of Paanini, Patanjali, the author, has raised many other grammatical issues and after discussing them fully and thoroughly, given his conclusions which have become the final dicta in those matters. The work, in short, has become an encyclopedic one and hence aptly called खनि or अकर. The work is spread over such a wide field of grammatical studies that not a single grammatical issue appears to have been left out. The author appears to have made a close study of the method and explanations of the SUtras of Paanini given at various academies all over the country and incorporated the gist of those studies given in the form of Varttikas at the various places, in his great work He has thoroughly scrutinized and commented upon the Vaarttikas many of which he has approved, some of which he has rejected, and a few of which he has supplemented. Besides the Vaarttikas which are referred to above, he has quoted stanzas which verily sum up the arguments in explanation of the difficult sUtras, composed by his predecessors. There is a good reason to believe that there were small glosses or commentaries on the SUtras of Paanini, written by learned teachers at the various academies, and the Vaarttikas formed in a way, a short pithy summary of those glosses or Vrttis. . The explanation of the word वृत्तौ साधु वार्तिकम् given by Kaiyata may be quoted in support of this point. Kaiyata has at one place even stated that the argument of the Bhaasyakaara is in consonance with that of Kuni, his predecessor. The work is divided into eighty five sections which are given the name of lesson or आह्लिक by the author, probably because they form the subject matter of one day's study each, if the student has already made a thorough study of the subject and is very sharp in intelligence. cf. अह्ला निर्वृत्तम् आह्लिकम्, (the explanation given by the commentatiors).Many commentary works were written on this magnum opus of Patanjali during the long period of twenty centuries upto this time under the names टीका, टिप्पणी, दीपिका, प्रकाशिका, व्याख्या, रत्नावली, स्पूर्ति, वृत्ति, प्रदीप, व्याख्यानं and the like, but only one of them the 'Pradipa' of कैयटीपाध्याय, is found complete. The learned commentary by Bhartrhari, written a few centuries before the Pradipa, is available only in a fragment and that too, in a manuscript form copied down from the original one from time to time by the scribes very carelessly. Two other commentaries which are comparatively modern, written by Naarayanasesa and Nilakantha are available but they are also incomplete and in a manuscript form. Possibly Kaiyatabhatta's Pradipa threw into the background the commentaries of his predecessors and no grammarian after Kaiyata dared write a commentary superior to Kaiyata's Pradipa or, if he began, he had to abandon his work in the middle. The commentary of Kaiyata is such a scholarly one and so written to the point that later commentators have almost identified the original Bhasya with the commentary Pradipa and many a time expressed the two words Bhasya and Kaiyata in the same breath as भाष्यकैयटयोः (एतदुक्तम् or स्पष्टमेतत्).