首楞嚴義疏注經 4.202

4.202

悟藏體也。不滅不生，無生智也。如來藏，無相理也。理智冥契，故名為合。當爾之時唯一妙心，無理智別，即始覺合本，無本始異，唯一覺故，故云唯妙覺明，圓照法界。

This is awakening to the essence of the [tathāgata]garbha. 'Neither perishes nor arises' is the wisdom of non-arising. The tathāgatagarbha is the principle without characteristics. Principle and wisdom tacitly tally, hence it is called 'unite'. At that very time there is only one wonderful mind, without any distinction between principle and wisdom; that is, initial enlightenment unites with the fundamental, without difference between fundamental and initial, because there is only one enlightenment; hence it says 'solely wonderful enlightenment and clarity, completely illuminating the dharmadhātu.'