Verse 16

चिरं हुताशवच्छुष्कपर्णान्येवाथ भक्षयन् ।पर्णाद इति नामासौ प्राप मध्ये तपस्विनाम्

In plain words

For a long time, thus devouring only dry leaves, as fire devours, he came to bear, among the ascetics, the name Parṇāda.