How to get a reluctant person to go to a psychologist/counsellor?

My parents are in their late 60s currently and my father started accusing my mom of cheating on him 10yrs ago. It has been 2 weeks and he is going really wild with these accusations now. Today he even planned and beat her with a belt couple of times. (Fyi, my parents dont stay with me so far - they were supposed to move in closer to my place by the end of this month) So far I have been very respectful in talking to him despite all the crazy shit he was saying/behaving. I have been urging him to talk to someone (of his own choice) that can help. Being from a very very patriarchal conservative upbringing, he doesn’t want to talk to anyone at all. Any pointers on how to get him help?