大毘盧遮那經供養次第法疏 2.6

2.6

三、宗趣者，盡心供養本尊，本尊領受，以為宗也，來世作佛為趣也。

Third, the main doctrine and purport: making offerings with all one's heart to the iṣṭadevatā and the iṣṭadevatā accepting them constitutes the main doctrine; becoming a Buddha in future lifetimes constitutes the purport.