言う事とする事は別問題だ。の英語

To say is one thing, and to do is another.

Saying is quite different from doing.

To say is one thing, to do is another.

Saying and doing are two different things.

If you insist.

That is another matter.

That's another matter.

If you have something to say, just say it.

Stop, I say.

I told you to stop, didn't I?

Don't state the obvious.

That's another question.

To say so is already a mistake.

That's another question.

That's another question―（問題外の意味なら）―beside the question―aside from the subject.

To say so is already a mistake.

in a manner of speaking

That's quite another matter.

Don't put it that way.

That is quite another matter.

Don't take any notice of what he says.

Talking is one thing, doing is another.

That is quite a different matter [another story].

Don't talk rubbish.

Just listen to what I'm saying, already.

That's a whole different matter.

It is bad English to say so.

Never say good-bye.

Don't say such childish things.

You may speak without reserve.