大毘盧遮那成佛經疏 2.76

2.76

第四十七「云何板心？謂順修隨量法，捨棄餘善故」者，如板在水中，隨其分量受載諸物，過限則不能勝，終亦傾棄之。此人心亦爾，簡擇善法業，隨己力分行一事已便作是語：「我承上以來唯行此法，不知其他。」乃至習行八齋即不捨離，更不慕行餘善。以發廣大心學菩提行，是所對治。

As for the forty-seventh, “What is the board-like mind? It refers to conforming to and practicing dharmas according to measure, discarding other good [practices]”: Just as a board in the water carries various items according to its capacity, but when over the limit it cannot bear them and will ultimately tip over and discard them, this person's mind is also like this. Selecting good dharmas and karmas, once they have performed a single matter according to their own capacity, they make this statement: “From the time I received [teachings] from my predecessors, I have only practiced this dharma and know no other.” Even to the extent that when practicing the eight precepts, they do not abandon them, and do not further admire or practice other good deeds. Cultivating the conduct of bodhi by generating a vast mind is the antidote.