摩訶止觀 2.18

2.18

Regarding vocal speech and silence: for ninety days, the body constantly walks without resting; for ninety days, the mouth constantly chants the name of Amitābha Buddha without resting; for ninety days, the mind constantly contemplates Amitābha Buddha without resting. Either chant and contemplate simultaneously, or contemplate first and chant later, or chant first and contemplate later, chanting and contemplating in succession with no time of rest. If one chants Amitābha, that is chanting the merits of the Buddhas of the ten directions and so forth, yet one exclusively takes Amitābha as the master of the Dharma gate. To sum up the essentials: step by step, sound by sound, thought-moment by thought-moment, be solely on Amitābha Buddha.