Matsya Purana 273.48

273.48

upasthāsyanti tānviprāstadarthamabhilipsavaḥ.
krameṇaiva ca dṛśyante svavarṇāntaradāyakam .. 273.47

Those Brâhmanas will adore such Śudras anxious to acquire wealth from them (or anxious to get the meaning of the Mantras from them) And gradually there will be seen all the causes which go towards the removing of a man from his own caste —48