大方廣佛華嚴經疏 6.49

6.49

第五初禪長行十法中，一普住等者，大用應機故普遍說法，用而常寂故行淨無染。得心無行故行淨，了境無相故無染。

Fifth, among the ten dharmas of the prose on the first dhyāna: First, regarding 'universally abiding' and so forth: because the great function responds to capacities, he universally expounds the Dharma; because he acts while remaining ever quiescent, his practice is pure and unstained. By attaining a mind without conduct, his practice is pure; by comprehending that objects are markless, he is unstained.