金剛經纂要刊定記 3.207

3.207

渴飲者，喻也。如渴飲水，但恐水竭無暇別觀。聽法之者，亦復如是。思冀妙門無心睥睨。

On "Drinking when thirsty": a metaphor. Like drinking water when thirsty, one only fears that the water will run out and has no leisure to look elsewhere. The listener to the Dharma is also like this: yearning for the wondrous gate, having no mind for looking askance.