首楞嚴義疏注經 5.287

5.287

從於眼識發顯智光，智光極處即佛知見，即三智、五眼一時具足，故名為極。

From the eye-consciousness, the light of wisdom is brought forth and manifested; the utmost of this light of wisdom is the Buddha's knowledge and vision, wherein the three wisdoms and five eyes are all simultaneously complete; therefore it is called 'utmost'.