A very barley with a pure heart to a Brahmana, acquired poor Brahmana by giving only a portion of powered the region of Brahman himself. This is a sufficient proof.
शुद्धेन मनसा दत्त्वा सक्तुप्रस्थं द्विजातये। ब्रह्मलोकमनुप्राप्तः पर्याप्तं तन्निदर्शनम्॥