Bhagavad Gita: Chapter 2, Verse 19

य एनं वेत्ति हन्तारं यश्चैनं मन्यते हतम् ।
उभौ तौ न विजानीतो नायं हन्ति न हन्यते ॥ २-१९ ॥

ya enaṁ vetti hantāraṁ yaś cainaṁ manyate hatam
ubhau tau na vijānīto nāyaṁ hanti na hanyate 2.19

He who thinks of this one as the killer, and he who thinks of this one as to be killed, both of them do not know. This one does not kill, nor it can be killed.