Having studied the Vedas, the Brahmanas should perform sacrifices and officiate as priests. Resorting to their vows the Kshatriyas should perform sacrifices and never officiate as priests.
अधीत्य ब्राह्मणो वेदान् याजयेत यजेत वा। क्षत्रियो धनुराश्रित्य यजेच्चैव न याजयेत्॥