釋禪波羅蜜次第法門 2.133

2.133

Furthermore, for the sake of cultivating dhyāna, the practitioner maintains pure precepts, abandons the five hindrances, and throughout the initial and final watches of the night focuses with diligence without lapse—just like drilling for fire, which is never rested before it ignites; this is called vigor. As the Buddha told Ānanda: 'Because all Buddhas diligently practice vigor with single-mindedness, they attain sambodhi.' How much more so for the other wholesome paths and dharmas?