Aṅguttara Nikāya
Ekakanipātapāḷi
Accharāsaṅghātavaggo
AN1.51
'This shining, almsmen, mind. OK and that stained from visiting stains, that not having learned the commoner essentially does not fathom. From that not having learned, I say 'cultivation of mind does not exist for the commoner'.'
AN1.52
'This shining, almsmen, mind. OK and that liberated from visiting stains, that having learned the hearer of what is noble essentially does fathom. From that having learned, I say 'cultivation of mind does exist for the hearer of what is noble'.'