大乘起信論義疏 1.84

1.84

經本之中境界為風，何故論主無明為風？釋曰：經中據末，境界為風，論主尋本，無明為風。此等皆有飄動義故。又後義推真識為海，無明為風，起七識波；七識為海，境界為風，起六識波。

In the sūtra text, objects are the wind; why does the treatise master take avidyā as the wind? Explanation: In the sūtra, relying on the branches, objects are the wind; the treatise master, tracing back to the root, takes avidyā as the wind. These both have the meaning of stirring and blowing. Furthermore, a later interpretation deduces that the true consciousness is the ocean and avidyā is the wind, giving rise to the waves of the seventh consciousness; the seventh consciousness is the ocean and objects are the wind, giving rise to the waves of the six consciousnesses.