Thou shall not keep...

...wallet you found on a train longer than few hundred Egyptian flop-years. Freshly hatched wolverine concept of money knows not, thus if he ever finds a wallet with handful of coins and bank notes, he is vowed to examine the money interaction in the nearest liquor establishment.

Wallet he found to its previous owner must be returned, or effort of trying must be shown at least....or sign of regret that he hasn't tried, but he feels bad about it at some minimal, insignificant way.