Mahabharata 1.187.28

युधिष्ठिर उवाच · yudhiṣṭhira uvāca

सूक्ष्मो धर्मो महाराज नास्य विद्मो वयं गतिम्पूर्वेषामानुपूर्व्येण यातं वर्त्मानुयामहे

sūkṣmo dharmo mahārāja nāsya vidmo vayaṃ gatimpūrveṣāmānupūrvyeṇa yātaṃ vartmānuyāmahe

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