keep (your) hand in (something)

to continue to be involved in something.

Rick turned the business over to his son, but he comes in Fridays to keep his hand in.

• come up with something
• come what may
• come within an ace of
• come within an ace of doing something
• come within an ace of something
• come within an inch of
• come within an inch of doing something
• come within a whisker of
• come within a whisker of doing something
• come within a whisker of something
• come with the territory
• comings and goings
• commit something to memory
• commit to memory
• commit to memory something
• common ground
• common-or-garden
• common touch
• compare apples and oranges
• compare notes
• conk out
• connect the dots
• contradiction in terms
• contrary to popular belief
• contrary to popular opinion