As water in a skull and milk in a bag made of dog-skin become impure for the uncleanness of the vessels in which they are kept, so the Vedas become fruitless in a person who is not of good conduct.
कपाले यद्वदापः स्युः श्वदृतौ च यथा पयः। आश्रयस्थानदोषेण वृत्तहीने तथा श्रुतम्॥