大毘盧遮那成佛經疏 11.5

11.5

「由本自性常空故，緣起甚深難可見」者，此不可得空之自性，即是第一常住法佛之身。以離空非空等八顛倒相，是即甚深從緣起法，無為無作而能不動法界普應眾生，機應相關如月現清水。如是緣起法，不可思議也（空之自性常有，不是先無今有、已有還無，故謂空本性如是也）。

Regarding "Because its original intrinsic nature is constantly empty, / dependent origination is extremely profound and difficult to see": this unattainable intrinsic nature of emptiness is the foremost, eternally abiding body of the Dharma-Buddha. Because it is free from the eight erroneous notions of emptiness and non-emptiness, it is this very profound teaching of dependent origination; unconditioned and uncreated, it can universally respond to sentient beings without moving from the dharmadhātu, capacity and response correlating like the moon appearing in clear water. Such a teaching of dependent origination is inconceivable. (The intrinsic nature of emptiness is constantly existent; it is not that it was previously absent and now present, or previously present and now absent; hence it is said that the original nature of emptiness is like this.)