Please Keep My Grandfather in Your Prayers During This Difficult Time

Assalamu alaikum, everyone. My 89-year-old grandfather is in critical condition, and my family and I are going through a very trying period. While I understand that at his age, we must all ultimately return to Allah, it's still incredibly painful to face the possibility of losing him. He fell ill while I was away at university, and my parents, not wanting to worry me, didn't tell me how serious it was. By the time I returned, his condition had worsened significantly. He's having great difficulty moving and speaking. The doctors have helped him breathe more easily on one side, but he was unable to tolerate the same procedure on the other. We've been told his heart is only functioning at about 30%. I am making constant du'a for him and seeking Allah's mercy, but I've also heard that the prayers of strangers hold a special power. So I am humbly asking if you could please remember him in your du'as. I pray that Allah grants him shifa and that he may, by His will, have the chance to meet his future great-grandchild and see me graduate. Jazakum Allahu khairan for your kindness and compassion. May Allah ease the suffering of all those who are ill.