I would send him a very simple note saying "Thank you for depositing money into the account." You don't need to go into a lot of chatty conversation w/him right now.

I would think that he's feeling a bit guilty because of the holidays coming and by depositing money into the accounts, it makes him feel better and he can say he did the right thing.

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.