extraordinary perceptiveness; sharp insight
Rare yojijukugo; used in literary or classical contexts to describe exceptional insight, as if illuminating hidden truths.
No one can match his extraordinary perceptiveness.
明察 is a more common term for keen insight or discernment, while 燃犀之明 is a rare, classical yojijukugo with a similar meaning.
From a Chinese legend in which burning rhinoceros horn illuminates the depths of water, revealing hidden things; the exact historical derivation is uncertain, but the phrase is conventionally associated with penetrating insight.