大方廣佛華嚴經疏 54.6

54.6

二無為法界二者：一性淨門，在凡位中性恒淨故，真空一味無差別故；二離垢門。謂由對治方顯淨故，隨行淺深分十種故。

Second, the two for the unconditioned dharmadhātu: 1. the gate of intrinsic purity: because in the stage of ordinary beings its nature is constantly pure, and true emptiness is of one flavor without differentiation; 2. the gate of freedom from defilement: meaning that purity is only revealed by means of antidotes, and is divided into ten kinds according to the depth of practice.