Mahabharata 13.47.59

समवर्णासु जातानां विशेषोऽस्त्यपरो नृपविवाहवैशेष्यकृतः पूर्वः पूर्वो विशिष्यते

samavarṇāsu jātānāṃ viśeṣo'styaparo nṛpavivāhavaiśeṣyakṛtaḥ pūrvaḥ pūrvo viśiṣyate

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