He wants to see them beg for mercy.

他想亲眼看着他们求饶。

《牛津词典》

He was kneeling on the floor pleading for mercy.

他正跪在地板上请求宽恕。

《柯林斯英汉双解大词典》

I beg for mercy for my poor friend, Harlequin, who has never done the least harm in his life.

我为我可怜的朋友哈利昆求饶，他一生中从未做过哪怕是最轻微的伤害。

youdao

"She showed me your letter. She asks you for mercy."

VOA: special.2009.01.31

Defense lawyers appealed for mercy.

VOA: special.2010.01.07

Mr.Carr had expected Alfred's mother to come in nervously,shaking with fear, asking with wet eyes for a mercy for he son, but no,she was most calm and pleasant and was making Mr.Carr feel guilty.

VOA: special.2010.09.11

"I don't ask the court for mercy because Allah is the one that gives mercy, " he said.

BBC: Awol US soldier Naser Jason Abdo jailed for life

His appeals for mercy were turned down by the Pakistan government and the country's Supreme Court.

WSJ: Prisoner's Death Frays India-Pakistan Ties

The victim had written to the court asking for mercy to be shown to him.

BBC: Belfast man jailed for biting off part of his partner's ear