The father rejecting these funds can not really be because of gambling... Maybe the man had worked all his life and the son had it the easy way and the father couldn't stand the easy life the son was about to get on and only yo send the message was to reject the money to tell the son that life is not easy..you need to work for it, to enjoy it!

Besides, these articles sometimes to have the full story, maybe the man is a religious man and gambling is something that might be frowned upon and was trying to stick to his principles....whatever it is, give it time, the son will explain himself and they will find a way to agree on how to receive the monetary gift.