If a Brahmana well acquainted with the Vedas takes up arins and tries to kill you in battle, you may proceed against him for taking his life. By such an act the slayer does not become guilty of Brahmanicide.
प्रगृह्य शस्त्रमायान्तमपि वेदान्तगं रणे। जिघांसन्तं जिघांसीयान्न तेन ब्रह्महा भवेत्॥