There is an interesting story as to how Panini, the originator of Sanskrit grammar, received knowledge from Shiva.
He was supposed to be the dullest of the students in a group that was studying from a Guru in Taxila, Taksha Shila. The other boys were very intelligent. Panini was the most stupid, the least intelligent, very much belittled and made fun of by the students in the class.
He was deeply hurt that he was being cowed down by other students and that he could not understand anything that the teacher said. Almost in a desperate mood of disgust with everything, he went to the forest and deeply contemplated on Shiva.
He prayed, “O Lord! Bless me with Knowledge.”
It is said that Shiva appeared before him, danced and revolved His Dakka or Damaru fourteen times, and the following fourteen sounds were made: 1. Aiun, 2. Rlrk, 3. Aowng, 4. Ai ouch, 5. Ha ya va rat, 6. Lan, 7. Na ma nga na nam, 8. Jha bhanj, 9. Gha dha dhash, 10. Ja ba ga da das, 11. Kha pha chha tha tha cha ta tav, 12. Ka pay, 13. Sa sha sar, and 14. Hal.
All this constitutes the very essence of Sanskrit grammar. These sounds, meaningless as they may appear to us, became the foundation of Sanskrit grammar and Sanskrit literature.
So, Bhagavan can teach us without books and without the usual medium of instruction, by a thought, a sound, a look, a touch or a benign gesture.
Such a Master’s son is Sri Ganapati, Sri Ganesha!