大比丘三千威儀 1.69

1.69

欲坐禪復有五事：一者當隨時、二者當得安床、三者當得端坐、四者當得閑處、五者當得善知識。

When wishing to practice dhyāna meditation, there are further five matters: first, one must accord with the seasons; second, one must obtain a restful bed; third, one must be able to sit upright; fourth, one must obtain a secluded place; fifth, one must obtain a good spiritual friend (kalyāṇamitra).