who says?

who says?

According to whose authority? A: "You can't just take money from the register like that!" B: "Who says? I own the business, so it's technically my money." Who says I can't take another holiday already? I have the days to take, and it doesn't conflict with anyone else in the office.
See also: who

who ˈsays (...)?

(spoken) used to disagree with a statement or an opinion: Who says I can’t do it?
See also: who