it will never happen.

A raise in pay? That'll be the day!

Usage notes: said esp. to emphasize something you wish would happen

• let off easy
• let off steam
• let off the hook
• let on
• let out
• let out something
• let ride
• let rip
• let's face it
• Let's get the show on the road.
• Let's get this show on the road.
• let sleeping dogs lie
• let slide
• let slip
• let slip something
• let slip through fingers
• let slip through your fingers
• let someone alone
• let someone be
• let someone down
• let someone go
• let someone have it
• let someone in on
• let someone in on something
• let someone off