Mahabharata 13.96.1

भीष्म उवाच · bhīṣma uvāca

अत्रैवोदाहरन्तीममितिहासं पुरातनम्यद्वृत्तं तीर्थयात्रायां शपथं प्रति तच्छृणु

atraivodāharantīmamitihāsaṃ purātanamyadvṛttaṃ tīrthayātrāyāṃ śapathaṃ prati tacchṛṇu

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