摩訶止觀 5.24

5.24

禪為法界者，「能觀心性，名為上定」，即首楞嚴；不昧不亂，入王三昧，一切三昧悉入其中。

Dhyāna being the dharmadhātu: "Being able to contemplate the nature of the mind is called the supreme concentration," which is the Śūraṅgama; neither dimmed nor disordered, entering the king of samādhis, all samādhis are contained within it.