These are the three things which are considered as pure and sacred by the celestials and as such fit for the Brahmana's use, viz., that whose impurity is unknown, that which has been washed in water, and that which has been well spoken of.
त्रीणि देवाः पवित्राणि ब्राह्मणानामकल्पयन्। अदृष्टमद्भिर्निर्णिक्तं यच्च वाचा प्रशस्यते॥