guard one's tongue

But in this company I should warn you to guard your tongue.

Hang on now, and see you guard your tongue.

In future he must guard his tongue or risk everything.

The words were blurted out before he could guard his tongue.

For it was no longer enough that a man, to be safe, should guard his tongue.

He had to guard his tongue much more closely.

This time he would guard his tongue more closely.

You know I was never good at guarding my tongue.

There was no need to guard her tongue or to watch her back.

Perhaps the pain will teach him to guard his tongue.