That man is to be regarded as a Brahmana whose religious practices remain ever unknown even to the members of his family among whom he lives, wise men also know him to be a Brahmana.
नित्यमज्ञातचर्या मे इति मन्येत ब्राह्मणः। ज्ञातीनां तु वसन् मध्ये तं विदुर्ब्राह्मणं बुधाः॥