The fourth and final tetrad is about purification: washing the mind the way dye is drawn out of white cloth, until what remains is bright awareness. Working through impermanence, fading away, cessation, and letting go, it treats the five poisons — greed, hatred, delusion, pride, and jealousy — as the dye to be bleached and worn out.

In this teaching, Lama Mark Webber is giving instruction on the practice of Anapanasati. The teachings were given in 2011 in Switzerland.