FORMULA displays the formula of a formula cell at any position.
The formula is returned as a string in the `reference` position.
If no formula cell can be found, or if the presented argument is not
a reference, the error value `#N/A` is
set.

FORMULA(`reference`)

The cell A8 contains the result of a formula having the value 23. You can use the FORMULA function in cell A1 to display the formula in cell A8.