Auru's Memo

From Zelda Wiki.org

Auru's Memo is received in Twilight Princess after talking with Auru after getting the Master Sword. When talking to Auru, answer yes to going into the desert, and he will give you the memo. When shown to Fyer, it allows the player to take the Oasis Flight into the desert. Auru tells Link that Fyer owes him, and that he will pass on the favor to Link.