Mahabharata 14.47.15
द्वावेतौ पक्षिणौ नित्यौ सखायौ चाप्यचेतनौएताभ्यां तु परो यस्य चेतनावानिति स्मृतः
dvāvetau pakṣiṇau nityau sakhāyau cāpyacetanauetābhyāṃ tu paro yasya cetanāvāniti smṛtaḥ
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book