You cannot unsay a cruel word.

你不能不说一句伤害人的话。

I will never unsay my words.

我决不收回自己所说的话。

What is said cannot be easily unsay.

说出来的话不易取消。

I will unsay no words that I've spoken about it.

我不想收回我对此所说过的话。

She wishes that she could unsay her words at the meeting.

她想要是能够收回在会上说的话就好了。

I wish I could unsay the sharp words to him. He must hate me very much.

真希望我没说那些过分的话，他一定恨死我了。