大比丘三千威儀 1.18

1.18

上雖知沙門儀法種種別異，未論出家人所作業務。業務者，一者坐禪、二者誦經法、三者勸化眾事。若具足作三業者，是應出家人法。若不行者，徒生徒死，或有受苦之因。

Although the various distinctions of the deportment and rules of a śramaṇa have been understood above, the engagements and tasks to be performed by a renunciant have not yet been discussed. As for tasks: first, sitting in meditation; second, reciting the scriptures and Dharma; third, exhorting and converting in various affairs. If one fully carries out these three tasks, this conforms to the norm for a renunciant. If one does not practice them, one lives in vain and dies in vain, and there will be causes for suffering.