In order to prove the identity of Bādarāyaṇa and Vyāsa (and therefore of the author of the Vedāntasūtra and the teacher of Jaimini, author of the Mīmāṃsāsūtra), Veṅkaṭanātha quotes a verse explaining how the name `Bādarāyaṇa’ came about:
dvīpe badarīkāmiśre bādarāyaṇam acyutam | parāśarāt satyavatī putraṃ lebhe parantapam ||
In the island mixed with (i.e., endowed with) Badarikā (jujube) trees, out of Parāśara, Satyavatī [the mother of Vyāsa] begot a child, a destroyer of foes, Bādarāyana, the imperishable.
Unlike with the previous verses about Bādarāyaṇa, all coming from the Mahābhārata, Veṅkaṭanātha does not mention his source in this case. Do readers have every encountered this verse?
It seems you asked pretty much the same question before (http://elisafreschi.com/2014/07/28/are-badaraya%E1%B9%87a-and-vyasa-the-same-person/ ).
Sudarśana Sūri quotes this verse in his Śrutaprakāśikā (top of p. 59 in 1937 edition of Śrībhāṣya with commentaries, vol. 1). He attributes it to ‘the Maharṣi himself’, by which he surely means Vyāsa. Probably he quotes it from a Purāṇic source.
The first line is close to Matsyapurāṇa 14.16ab; but I can’t cite a Purāṇic source for the second half at the moment.
H.I.
Well, I am happy I asked the question again, since I could receive this interesting answer! Many thanks!