This is a subjunctive present. It was used to mark a hypothetical situation. It has almost entirely vanished from the living language.
if I,you,he,she,it,we,they say/move/be.
The only locution that still uses it sometimes is the demand or request:
The government demanded that the guerillas stop their insurgency.
I demand that you give me the book.
I'd like to request that he refrain from calling me all day.
Student or Learner