If you say to someone ' take it or leave it ', you are telling them that they can accept something or not accept it, but that you are not prepared to discuss any other alternatives .
take leave of one's senses
to go mad or become irrational
take (or leave) the field
to begin (or withdraw from) activity in a game, military operation , etc.
take one's leave/take leave of sb
When you take your leave or take leave of someone, you say goodbye and go .
have taken leave of one's senses
If you say that someone seems to have taken leave of their senses , you mean that they have done or said something very foolish.