大方廣佛華嚴經隨疏演義鈔 24.62

24.62

疏「謂若自相」等者，謂觀色等六塵入正定，故名為自相。若觀無常空等八定，則名共相。並皆不離如來藏性，性即真如故。《起信論》云「真如三昧是諸三昧根本。」上釋出生一切諸三昧法。

In the commentary, as for 'Meaning that if own-characteristics' and so forth, it means contemplating the six sense-data such as visible form to enter correct concentration, hence called own-characteristics. If contemplating the eight concentrations such as impermanence and emptiness, they are called common characteristics. None of them depart from the nature of the tathāgatagarbha, because the nature is tathatā. The Awakening of Faith says: 'The tathatā samādhi is the root of all samādhis.' The above explains producing all samādhi dharmas.