Somavaṃśa-prasavaḥ
Birth of the Lunar Line: Budha–Purūravas and the Urvaśī Episode
तपसा तु सुतप्तेन लोकान्विष्टभ्य तिष्ठति / सत्यं तु तपसः श्रेयस्तस्माज्ज्ञानं गुरु स्मृतम्
tapasā tu sutaptena lokānviṣṭabhya tiṣṭhati / satyaṃ tu tapasaḥ śreyastasmājjñānaṃ guru smṛtam
By well-performed austerity he stands firm, upholding the worlds. Yet truth is higher than austerity; therefore wisdom is remembered as the true guru.