负荆请罪

fùjīng-qǐngzuì

[proffer a birch and ask for a flogging; apology for wrong-doing; be contrite and ask for pardon; carry a rod on one's back and ask to be punished; carry firewood and ask to be spanked] 背上荆条请求责罚。 表示真诚地认罪赔礼

我则做小, 负荆请罪。 --《元曲选外编·渑池会》