THE LIFE OF THE BUDDHA: CHAPTER IV – PLOUGHING FESTIVAL
Every year there was a big festival at the time the rice fields were ploughed. One day King Suddhodana took the little Prince to the ploughing festival. The Prince fell asleep. Seeing that the Prince was sleeping, His maids joined in the festivities of the day.
When they came back they found the Prince deep in meditation. He was meditating on His breathing in and breathing out. This meditation is known as breathing meditation (Aanaapaana Sati Meditation). This form of meditation is very important, as it was this meditation that was later used by the Buddha to attain enlightenment (*).
(*) enlightenment – the supreme knowledge that leads to the end of rebirth.
Source: Budsas.net