Siksa, Vyakarna and the subjects I have yet to deal with -Chandas and Nirukta-are Vedangas-(limbs of the vedas)connected with language. After I said that I would deal with matters basic to our religion, I have been speaking about linguistic studies and grammar. Next I am going to deal with prosody. By works on religion we ordinarily mean those[directly] relating to God, worship, devotion, jnana, dharma and so on. Would not the right thing for me then be to speak about such works?
When we dealt with the vedas a number of matters cropped up, matters regarded as germane to religion. Religion will find a prominent place in the subjects that I have yet to speak about, Kalpa, Mimamsa, the Puranas and Dharmasastra., But in between has arisen the science of language that has apparently no connection with religion.
In the vedic view everything is connected with the Lord. There is no question of dividing subjects into "religious" and "non-religious". Even the science of medicine, Ayurveda, which pertains to physical well being, is ultimately meant for Atmic uplift- or for that matter, military science(Dhanurveda). That is why they were made part of traditional lore. So too political economy which is also an Atma-sastra.
Why are works belonging to these fields held in great esteem? All subjects, all works, that teach a man to bring order, refinement and purity in every aspect of his life and help him thus to take the path to liberation are regarded as religious in character.
Sound is the highest of the perceived forms of the Paramatman and language is obviously connected with it. It is the concern of Siksa and Vyakarana to refine and clarify it and make it a means for the well-being of our Self.
Grammar is associated with Sabdabrahman. Worship of the Nadabrahman which is the goal of music is a branch of this. If sounds are well discerned and employed in speech they will serve not only the purpose of communication but also of cleansing us inwardly. The science of language is helpful here.
I have already mentioned that Pathanjali's commentary on Panini's Sutras is called the Mahabhasya. The prefix "Maha" in the name of the work is an indication of high degree of importance given to grammar in our tradition. Illustrious teachers have written commentaries on the Vedas, on the Brahmasutra, on the Upanisads, on the Bhagavadgita, and so on. But none of these has "maha" prefixed to it. There is a saying that a scholar derives as much happiness from learning the Mahabhasya as from ruling an empire.
Mahabhasyam va pathaniyam
maharajyam va sasaniyam
I recently came across another piece of evidence like the Vengi inscription to prove how in the old days our rulers nurtured and propagated the science of grammar.
Dhar was a state in the formal Central Provinces(now a part of Madhya Pradesh). It is the same as Dhara which was the capital of Bhojaraja who was a great patron of arts and who made lavish gifts to poets and artists. There is a mosque in the town of Dhar now. Once a cave was discovered in the mosque which on examination revealed some writings in Sanskrit. But the department of epigraphy could not carry out any investigations until some years after freedom. Then, with the permission of the authorities of the mosque, they studied their finding.
To their amazement they saw a wheel inside with verses dealing with grammar inscribed on it in the form of a chart. The mosque stands today where a temple to Sarasvati stood during Bhojaraja's time. The idea behind the wheel is that the science of language (grammar)must form part of the temple to Sarasvati, the goddess of speech---and grammar is the Vedapurusa's mouth. They say that grammar could be learnt at a glance from this wheel. It is because the science of language is worthy of worship that the wheel inscribed with grammar was installed in the temple. With the blessings of Vagdevi(Sarasvati) we have obtained the wheel, though long after the mosque was built at that site. The department of epigraphy has published the text of the inscription with an English translation.
We learn thus that sastras like grammar were not regarded merely as of worldly interest but in fact considered worthy of worship. That is why rulers promoted them.
For a general background, please see here