淨名經集解關中疏 2.392

2.392

如是阿難。諸佛威儀進止。諸所施無為非佛事　法身無為應物故進止威儀皆佛事也。

"Thus, Ānanda, of all the demeanour, movements, and actions of the Buddhas, there is nothing done that is unconditioned that is not the Buddha's work." The unconditioned nature of the dharmakāya responds to beings, therefore all movements and demeanours are Buddha's work.