if you do something as quick as a flash, you do it very quickly.

Quick as a flash, he snatched the book and ran out of the room.

• raise your hackles
• raise your hand against
• raise your hand against someone
• raise your hand to
• raise your hand to someone
• rake in
• rake in something
• rake-off
• rake over the ashes
• rake over the coals
• ram down someone's throat
• ram down throat
• ramp up
• ramp up something
• ram something down someone's throat
• ram something down throat
• rank-and-file
• rank and file
• rap across the knuckles
• rap knuckles
• rap on the knuckles
• rap over the knuckles
• rap sheet
• rap someone's knuckles
• raring to go