[39] The Blessed One said this: "'Killing of living beings (pāṇātipāta) should be given up in reliance upon the non-killing of living beings' — thus indeed was this said. And in dependence on what was it said? Here, householder, a noble disciple reflects thus: 'I am practicing for the abandoning and cutting off of those fetters (saṃyojana) on account of which I might be a killer of living beings. And if I were a killer of living beings, I myself would reproach myself on account of the killing of living beings; the wise, having investigated, would censure me on account of the killing of living beings; and with the breakup of the body, after death, a bad destination is to be expected on account of the killing of living beings. This very killing of living beings is itself a fetter, itself a hindrance (nīvaraṇa). And whatever taints (āsava), distressing and feverish, might arise on account of the killing of living beings — for one who abstains from killing living beings, those taints, distressing and feverish, do not exist.' 'Killing of living beings should be given up in reliance upon the non-killing of living beings' — thus what was said, it was said in dependence on this."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.