Kathasaritsagara 1.4.25

Now in course of time Varsha got a great number of pupils, and among them there was one rather stupid pupil of the name of Panini; he, being wearied out with service, was sent away by the preceptor's wife, and being disgusted at it and longing for learning, he went to the Himalaya to perform austerities: then he obtained from the god, who wears the moon as a crest, propitiated by his severe austerities, a new grammar, the source of all learning. Thereupon he came and challenged me to a disputation, and seven days passed away in the course of our disputation; on the eighth day he had been fairly conquered by me, but immediately afterwards a terrible menacing sound was uttered by Siva in the firmament; owing to that our Aindra grammar was exploded in the world, and all of us, being conquered by Panini, became accounted fools. Accordingly full of despondency I deposited in the hand of the merchant Hiranyadatta my wealth for the maintenance of my house, and after informing Upakosa of it, I went fasting to mount Himalaya to propitiate S'iva with austerities.

Now in course of time Varsha got a great number of pupils, and among them there was one rather stupid pupil of the name of Panini; he, being wearied out with service, was sent away by the preceptor's wife, and being disgusted at it and longing for learning, he went to the Himalaya to perform austerities: then he obtained from the god, who wears the moon as a crest, propitiated by his severe austerities, a new grammar, the source of all learning. Thereupon he came and challenged me to a disputation, and seven days passed away in the course of our disputation; on the eighth day he had been fairly conquered by me, but immediately afterwards a terrible menacing sound was uttered by Siva in the firmament; owing to that our Aindra grammar was exploded in the world, and all of us, being conquered by Panini, became accounted fools. Accordingly full of despondency I deposited in the hand of the merchant Hiranyadatta my wealth for the maintenance of my house, and after informing Upakosa of it, I went fasting to mount Himalaya to propitiate S'iva with austerities.