耕当问奴，织当访婢

gēng dāng wèn nú , zhī dāng fǎng bì

if it's plowing ask the laborer, if it's weaving ask the maid (idiom); when managing a matter, consult the appropriate specialist

耕

gēng

to plow

当

dāng

to be

问

wèn

to ask; to inquire

奴

nú

slave

，

,

织

zhī

to weave

当

dāng

to be

访

fǎng

(bound form) to seek by inquiry

婢

bì

slave girl