Mahabharata 3.81.126

उत्तमे सर्वतीर्थानां यस्त्यजेदात्मनस्तनुम्पृथूदके जप्यपरो नैनं श्वोमरणं तपेत्

uttame sarvatīrthānāṃ yastyajedātmanastanumpṛthūdake japyaparo nainaṃ śvomaraṇaṃ tapet

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