Mahabharata 3.80.38

ऋषीणां परमं गुह्यमिदं भरतसत्तमतीर्थाभिगमनं पुण्यं यज्ञैरपि विशिष्यते

ṛṣīṇāṃ paramaṃ guhyamidaṃ bharatasattamatīrthābhigamanaṃ puṇyaṃ yajñairapi viśiṣyate

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