Mahabharata 12.201.6
अत्रिवंशसमुत्पन्नो ब्रह्मयोनिः सनातनःप्राचीनबर्हिर्भगवांस्तस्मात्प्राचेतसो दश
atrivaṃśasamutpanno brahmayoniḥ sanātanaḥprācīnabarhirbhagavāṃstasmātprācetaso daśa
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book