In this (work) the sacred law has been fully stated as well as the good and bad qualities of (human) actions and the immemorial rule of conduct, (to be followed) by all the four castes (varna).
आचारः परमो धर्मः श्रुत्योक्तः स्मार्त एव च । तस्मादस्मिन् सदा युक्तो नित्यं स्यादात्मवान् द्विजः ॥ १०८ ॥
The rule of conduct is transcendent law, whether it be taught in the revealed texts or in the sacred tradition; hence a twice-born man who possesses regard for himself, should be always careful to (follow) it.