In the Anguttara Nikaya (sutta i, 21) the buddha states,
“there is one thing, monks, that, cultivated and regularly
practiced leads to a deep sense of urgency...to the supreme peace...to mindfulness and clear comprehension...to the attainment of right vision and knowledge...to happiness here and now...to realizing deliverance by wisdom and the fruition of holiness:
it is mindfulness of the body.”