यस्य नाहंकृतो भावो बुद्धिर्यस्य न लिप्यते। हत्वापि स इमाँल्लोकान्न हन्ति न निबध्यते ॥

yasya nāhankṛito bhāvo buddhir yasya na lipyate hatvā ‘pi sa imāl lokān na hanti na nibadhyate

He who is free from the egoistic notion, whose Reason is not affected, though he slay these peoples, he slayeth not, nor is bound.

In plain words: Krishna says a person with no selfish sense of "I am the doer," whose mind is not stained, does not really kill even when killing in battle. That person is not bound by the action.