Ruling on sons leaving their father unattended in the hospital

A man fell ill, and he has two sons who are employed and married, while he also has other sons who have independent businesses. He needed someone to accompany him in the hospital, but none of the sons was able to do so, so they hired a worker to be with him to comfort him. The father is still cursing them. Is their conscience cleared by hiring a worker? And will any of his cursing affect them? Please give us a ruling, may Allah reward you.
Are these men occupied with work that prevents them from being present with their father? If they have something that prevents them from being with their father, they are excused, such as being employed, for an employee cannot come during work hours. However, if they are not excused and nothing would harm them if they were present, then they are sinful, and it is feared that their father’s cursing will affect them; for the compassion of a worker is not like the compassion of a son, and the comfort a sick father finds in a worker is not like the comfort he finds in them. So let them know that if there is no legitimate religious excuse preventing them from accompanying their father, they must accompany him, or else they should beware of the punishment.