Let sleeping dogs lie
If someone is told to let sleeping dogs lie, it means that they shouldn't disturb a situation as it would result in trouble or complications.
to blow one's own trumpet
to vaunt one's own exploits, or sound one's own praises, to boast
to bury the hatchet
to lay aside the instruments of war, and make peace; to make peace or become reconciled - a phrase used in allusion to the custom observed by the North American Indians, of burying a tomahawk when they conclude a war.
- For Teachers