Answer:
"The face of the instrument"
Step-by-step explanation:
This is a legal phrase which means the contract (aka the "instrument") must be read "on its face." Basically, you should put everything you want the contract to say in plain language and the parties are only held to the plain, common understanding of exactly what is written down.
The idea is that no party can go back and say that something else is expected or implied from the contract unless it is actually written down.