華嚴經探玄記 18.36

18.36

三所說經，從所詮立名，謂智用宏舒名為普照，所照深廣稱為法界，即是入法界經也。具足主伴，是圓教法門。

Third, the sūtra preached is named from the signified: the vast extension of the function of wisdom is called 'universal illumination', and the depth and breadth illuminated is called the 'dharmadhātu'—that is, the Sūtra of Entering the Dharmadhātu. Being complete with host and retinue, it is the Dharma gate of the perfect teaching.