大方廣佛華嚴經疏 17.19

17.19

三宗趣者，以集眾放光偈讚為宗，為成正說為趣。又顯佛德為宗，令知住體為趣。

Third, the central theme and purport: taking the gathering of the assembly, the emission of light, and the verses of praise as the central theme, and bringing about the primary exposition as the purport. Furthermore, revealing the Buddha's virtues is the central theme, and causing one to know the essence of the abodes is the purport.