Mahabharata 1.2.201

अत ऊर्ध्वं तु विज्ञेयमानुशासनमुत्तमम्यत्र प्रकृतिमापन्नः श्रुत्वा धर्मविनिश्चयम्भीष्माद्भागीरथीपुत्रात्कुरुराजो युधिष्ठिरः

ata ūrdhvaṃ tu vijñeyamānuśāsanamuttamamyatra prakṛtimāpannaḥ śrutvā dharmaviniścayambhīṣmādbhāgīrathīputrātkururājo yudhiṣṭhiraḥ

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