Mahabharata 3.155.76

वदन्ति मधुरा वाचः सर्वभूतमनोनुगाःभृङ्गराजोपचक्राश्च लोहपृष्ठाश्च पत्रिणः

vadanti madhurā vācaḥ sarvabhūtamanonugāḥbhṛṅgarājopacakrāśca lohapṛṣṭhāśca patriṇaḥ

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