cheddar

"Cheddar" as slang for money comes from Cheddar cheese, likely through the old association of cheese with wealth.

That link to wealth may trace back to the Persian word "چیز" (čiz), meaning simply "thing," before the slang settled on cheese as its image of riches.

It's tied to the Persian word čiz, meaning "thing," which may sit behind the whole chain of association with wealth.