金剛經纂要刊定記 5.114

5.114

徵意云：所以令無我等相者，何謂也？釋意云：以我等相即非相故，我相體是心心所法，既無此體即是法空也。

The intent of the query is: what does it mean to cause them to be free from the marks of a self and so forth? The intent of the explanation is: because the marks of a self and so forth are non-marks; the essence of the mark of a self is mind and mental factors, and since this essence is absent, this is the emptiness of phenomena.