“Do you wish to come with me tonight?”

“Yes,” said Harry at once.

“Very well, then: Listen.” Dumbledore drew himself up to his full height. “I take you with me on one condition: that you obey any command I might give you at once, and without question.”
“Of course.”
“Be sure to understand me, Harry. I mean you must follow even such orders as ‘run,’ ‘hide,’ or ‘go back.’ Do I have your word?”
“I — yes, of course.”

“If I tell you to hide, you will do so?”

“Yes.”
“If I tell you to flee, you will obey?”
“Yes.”
“If I tell you to leave me and save yourself, you will do as I tell you?”
“I —”
“Harry?”
They looked at each other for a moment.

“Yes, sir.”

Harry Potter and the Half-Blood Prince – J.K. Rowling