Mahabharata 3.206.4

शूद्रयोनौ वर्तमानो धर्मज्ञो भविता ह्यसिमातापित्रोश्च शुश्रूषां करिष्यसि न संशयः

śūdrayonau vartamāno dharmajño bhavitā hyasimātāpitrośca śuśrūṣāṃ kariṣyasi na saṃśayaḥ

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