大方廣佛華嚴經隨疏演義鈔 52.7

52.7

疏「將證離欲」下，二通釋第六天義。以是欲界之頂，隣梵天故。色界梵天即是離欲，如於佛位。今明十地，如在第六希欲，將昇隣極證故。

Regarding the commentary's "Being about to realize detachment from desire" and so forth: second, generally explaining the meaning of the sixth heaven. Because it is the pinnacle of the desire realm, it is adjacent to the Brahmā heaven. The Brahmā heaven of the form realm is detachment from desire, analogous to the Buddha stage. Here clarifying the ten stages is like being in the sixth heaven, aspiring beyond desire, about to ascend and realize adjacency to the ultimate.