The Buddha taught His disciple Upanishad this practice to help him overcome his strong sexual desires. Upanishad’s name means “the emptiness of the nature of form,” and it was through this practice that he was able to observe how his own physical body, as well as everyone else’s, was unclean, and thus was he able to become enlightened. See the Shuragama Sutra.
1. Contemplate swelling. After death, the body starts to swell up.
2. Contemplate the green mottled flesh. After the ‘swelling, the body breaks out in green areas like big bruises.
3. Contemplate flesh broken open. After it turns green, it pops open.
4. Contemplate blood and filth. When it breaks open, the blood and other things flow out.
5. Contemplate pus and rot. The pus begins to ooze out of the body as it starts to rot.
6. Contemplate it being eaten by worms. Out of the pus and rot emerge worms which feast on the flesh.
7. Contemplate it scattering. The flesh begins to fall off.
8. Contemplate the bare bones. Once the flesh is gone, there are just the bones underneath.
9. Contemplate it being burned. It is burned by the fire and turns into ashes. The ashes drift into emptiness and turn into dust, until at last there’s nothing left.