Walking and sitting/lying down: what is the difference?

While walking, the body consciousness and mind consciousness should be placed on the operation of the physical body, with attention on the physical body and the surrounding environment; the attention of the solitary consciousness (mano-vijñāna-eka-citta) on contemplating the meaning of the Dharma must be reduced, because there is not enough energy—one cannot be single-minded, the contemplation is not deep and subtle, and wisdom does not easily arise. Whereas in sitting and lying down, the conscious mind is less dispersed, the solitary consciousness is more concentrated, the contemplation becomes deep and meticulous, and wisdom easily arises.

Therefore it is said that meditative concentration in stillness while sitting or lying down more easily gives rise to wisdom. In sitting and lying down, the mind has no extra burdens; one can concentrate one's energy and contemplate meticulously, without worrying about what situations walking might encounter. With the mind at ease, it is easier for preparatory concentration (anāgamya-samādhi) and first dhyāna concentration to arise during sitting meditation.

Wisdom arises from meditative concentration—this concentration refers to preparatory concentration and first dhyāna concentration. Therefore, for realizing the fruits and for enlightenment, one must at minimum possess preparatory concentration. As long as it is not a thought-free preparatory concentration or first dhyāna concentration, with deep concentration the contemplation becomes even more meticulous, and there is no problem in opening wisdom and discovering a new continent.