Shiva Purana
सोऽवतारो विधे मे हि ऋषभाख्यस्सुयोगकृत् ॥ सारस्वतव्यासमनः कर्त्ता नानोतिकारकः ॥३९॥
O Brahmā, such is my incarnation named Ṛṣabha. It causes Yogic practice; it fulfils the desire of Vyāsa in the guise of Sārasvata and it consists of many divine sports.
english translation
so'vatAro vidhe me hi RSabhAkhyassuyogakRt ॥ sArasvatavyAsamanaH karttA nAnotikArakaH ॥39॥
hk transliteration by Sanscript