大乘起信論裂網疏 6.127

6.127

修行止者，對治凡夫樂著生死，亦治二乘執著生死而生怖畏。修行觀者，對治凡夫不修善根，亦治二乘不起大悲、狹小心過。是故止觀互相助成，不相捨離。若止觀不具，必不能得無上菩提。

"Cultivating calm abiding remedies the ordinary person's pleasure in and attachment to saṃsāra, and also remedies the two vehicles' clinging to saṃsāra and giving rise to fear. Cultivating special insight remedies the ordinary person's failure to cultivate roots of goodness, and also remedies the fault of the two vehicles' narrow-mindedness in not giving rise to great compassion. Therefore, calm abiding and special insight mutually assist and accomplish each other, never abandoning one another. If calm abiding and special insight are not complete, one will definitely not attain unsurpassed bodhi."