Flame Library

After making sure no one can hear them, Alvin instructed while using the slave contract, "First, if you find any kind of changes occurring to yourself, you'll immediately report them to me. 

"Second, never told Lan anything if he ever summoned you and report this back to me nor should you ever revile your identity to anyone! 

"Third, you'll have to study the skill I gave you for ten hours a day and report the results of it after a week to me, as for the remaining day, you're free to do anything besides revealing anything about element physique.

"Fourth, don't try to cultivate until I give you the order and remain low-key…." 

Alvin carefully impart many instructions to Finn while using the slave contract power, so Finn could not breach them. He didn't do it in front of Lan because he can't afford Lan's suspicion at the moment. Not until he can go back.