[500] Then, Prince, this occurred to me: 'Why should I not meditate the breathless meditation (appānaka jhāna) itself?' So, Prince, I stopped the in-breaths and out-breaths through the mouth, the nose, and the ear canals. When my in-breaths and out-breaths were stopped through the mouth, the nose, and the ear canals, there was an extreme burning in my body. Just as if, Prince, two strong men were to seize a weaker man by both arms and burn and scorch him over a pit of glowing coals, even so, Prince, when my in-breaths and out-breaths were stopped through the mouth, the nose, and the ear canals, there was an extreme burning in my body. And yet, Prince, my energy (vīriya) was aroused and unflagging, and my mindfulness (sati) was established and unconfused; but my body was overstrained and not tranquil, being of one overwhelmed by that very painful exertion.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.