大方廣佛華嚴經疏 21.8

21.8

初來意者，助化讚揚故、說行體性故、行所依故。然三天偈讚，來意宗趣大旨是同，但解行願以為異耳。釋名、宗趣亦不異前，約處約行少有別耳。

First, as for the intention of its occurrence: it is to assist transformation by praising and extolling, to expound the essence and nature of practice, and because it is that upon which practice relies. However, regarding the verses of praise in the three heavens, the general purport of their intention and central theme is largely the same, differing only in understanding, practice, and vow. The explanation of the name and the central theme also do not differ from the preceding, with only slight distinctions according to place and according to practice.