If he was my close friend, We, Chinese friends, would buy some nutritious food or fruits and go to see his father, sometimes we would give cash instead if we don't have time to buy these things. If we live in different cities, we would send a message along the lines of saying "希望你父亲早日康复“ “祝他早日恢复健康“

Hi, friend! I am sending this message, because I have heart that your are taking care of your father lately. I hope everything is going to be fine and I am looking forward to hearing from you some good news about it. If you need any help or my support, please don't hesitate to call me, even if you need somebody just to talk with.