Mahabharata 2.33.9

न तस्यां संनिधौ शूद्रः कश्चिदासीन्न चाव्रतःअन्तर्वेद्यां तदा राजन्युधिष्ठिरनिवेशने

na tasyāṃ saṃnidhau śūdraḥ kaścidāsīnna cāvrataḥantarvedyāṃ tadā rājanyudhiṣṭhiraniveśane

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