Mahabharata 14.50.16

ओषधान्यगदादीनी नानाविद्याश्च सर्वशःतपसैव प्रसिध्यन्ति तपोमूलं हि साधनम्

oṣadhānyagadādīnī nānāvidyāśca sarvaśaḥtapasaiva prasidhyanti tapomūlaṃ hi sādhanam

Our plain-language meaning of this verse is waiting for scholar review.