expression, nidan verb (lower class) with 'mu' ending (archaic)
to be nitpicky; to be fault-finding
Proverb meaning to find fault with something trivial or to be overly critical. Literally 'blow the fur to find a scar'. Archaic grammar (classical Nidan verb 求む).
He always says things that are nitpicky, like blowing the fur to find a scar.
そんな小さなミスを指摘するのは、毛を吹いて疵を求むようなものだ。
Pointing out such a small mistake is like being fault-finding.
Similar meaning: to nitpick or split hairs. 毛を吹いて疵を求む is more literary and archaic, while 重箱の隅をつつく is a common modern idiom.
From the classical Chinese expression 吹毛求疵, literally “blow apart hairs to seek a flaw,” describing the exposure or invention of tiny faults through excessive scrutiny.