hold your horses
wait a moment, slow down
cost an arm and a leg
very expensive
call it a day
stop working on something
break a leg
good luck
hit the sack
Go to sleep
pull someone's leg
to tell someone something that is not true, as a joke
Under the weather
Sick
a perfect storm
the worst possible situation
It's a piece of cake.
It's easy
It's raining cats and dogs.
It's raining hard
Once in a blue moon
Rarely
let the cat out of the bag
reveal a secret carelessly or by mistake, tell a secret
The ball is in someone's court.
It’s another person’s turn to make a decision.
like a bull in a china shop
very careless and clumsy in the way that they move or behave
Lunch is on me.
I'll pay for lunch.
You can't judge a book by its cover.
This person or thing may look bad, but it's good inside
