About This Teaching
Mentally reciting "Bud" on the in-breath and "dho" on the out-breath was the anchor Ajahn Chah recommended to meditators. The reading explains that the long "o" of Buddho is easier to sustain through an exhalation, and that the word names the very knowing being cultivated, so returning to its meaning keeps practice from becoming mechanical. Once the knowing of the breath was clear and stable, the mantra could be set aside.
In his own words, Buddho should penetrate deep into the heart, waking the mind up. Clear knowing brightens the mind like a light growing stronger in a darkened room, revealing ever more detail. Sati, mindfulness, depends on this knowing.
For those with no affinity for the breath, he encouraged contemplation of death or of the body, beginning with head hair, body hair, nails, teeth and skin, seen as unattractive or as elements. Because identification with the body is the strongest expression of personality view, body contemplation was highly valued. Seeing the body as "just that much" lets the mind release it.