Bhagavatapurana 2.10.49

2.10.49

kṣattuḥ kauśāravestasya saṃvādo 'dhyātmasaṃśritaḥ /
yadvā sa bhagavāṃstasmai pṛṣṭastattvam uvāca ha //

49 and 50. At what place he met *Kausharava* (Maitreya) and heard his discourse upon Atman (on Adhyatma subjects), what philosophical questions that worshipful sage was asked and what he explained to Vidura, please tell us, O gentle one, all about it, and also of all that Vidura did, why he abandoned his relations and why he came back."