Twice-born men may take up arms when (they are) hindered (in the fulfilment of their duties, when destruction (threatens) the twice-born castes (varna) in (evil) times,
आत्मनश्च परित्राणे दक्षिणानां च सङ्गरे । स्त्रीविप्राभ्युपपत्तौ च घ्नन् धर्मेण न दुष्यति ॥ ३४९ ॥
In their own defence, in a strife for the fees of officiating priests, and in order to protect women and Brahmanas; he who (under such circumstances) kills in the cause of right, commits no sin.
गुरुं वा बालवृद्धौ वा ब्राह्मणं वा बहुश्रुतम् । आततायिनमायान्तं हन्यादेवाविचारयन् ॥ ३५० ॥
One may slay without hesitation an assassin who approaches (with murderous intent), whether (he be one’s) teacher, a child or an aged man, or a Brahmana deeply versed in the Vedas.