Matsya Purana 198.8

198.8

parasparamavaivāhyā ṛṣayaḥ parikīrtitāḥ.
devaśravāḥ sujāteyāḥ sausukāḥ kārukāyanāḥ .. 198.7

They also do not intermarry among themselves. Daivaśravâ, Devarâta ; Viśvâmitra are the three Pravaras of Daivaśravâ, Sujâtaiyâ, Sansukâ, Kârukâya, Vaidaiharatâ, Kuśikâ. They also do not intermarry. Dhananjaya, Kapardaiya, Parîkûta, Pârthiha, Pânini have Viśvâmitra, Madhuchchhanda, Aghamarṣaṇa for their Pravaras. They also do not intermarry. Kamalâyajina, Aśmarathya, Bânjuli, are also the three Pravaras. They too do not intermarry.—7-14.