どばにむちうつ

駑馬に鞭打つ

to work hard; to keep one's nose to the grindstone; to whip a jaded horse

N3Expression
Expression, Godan verb (tsu ending)
to work hardto keep one's nose to the grindstoneto whip a jaded horse
Expression, Godan verb (tsu ending)
to make someone do what is beyond their ability