Mahabharata 13.48.38

युधिष्ठिर उवाच · yudhiṣṭhira uvāca

वर्णापेतमविज्ञातं नरं कलुषयोनिजम्आर्यरूपमिवानार्यं कथं विद्यामहे नृप

varṇāpetamavijñātaṃ naraṃ kaluṣayonijamāryarūpamivānāryaṃ kathaṃ vidyāmahe nṛpa

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