釋氏要覽 3.108

3.108

智論云。一切禪定攝心。皆名三摩提。秦言正心行處。謂是心從無始已來。常曲不端。得是正心行處。心則端直。如蛇入竹筒內。

The Mahāprajñāpāramitopadeśa states: "All dhyāna-absorption that collects the mind is called samādhi. In the language of Qin, it is called 'the state of rectifying mental activities.' This means that this mind has always been bent and not straight since beginningless time; when it attains this state of rectifying mental activities, the mind becomes upright and straight, like a snake entering a bamboo tube."