Abdullah ibn Mas’ud r.a.’s son died and the people came to visit him. But he was nowhere to be found. He was found in masjib nabawi praying salah. They asked why he was there, he said he felt aggrieved and so he prayed salah to give him peace.
This is why we have salatul janazah, to grant the person peace.
This ayah tells us that if shaheed is alive, then the Prophet ﷺ has more of a right to be alive. Since the shaheed has sacrificed his life to the deen, and so have the Prophets.
The awliyaa have a status even higher than a shaheed, as the hadith that mentions the one who maintains the sunnah, for him is the reward of a hundred shuhadaa.
Allah tests people, with fear when speaking the truth, with hunger to see if he lies to gain food, with wealth to see if he cheats, with family when they die to see if they show patience.
This ayah was revealed after the Battle of Uhud as 70 sahabah died.
The phrase “inna lillahi wa inna ilayhi raji’oon” has been brought specifically for our ummah. Those who use this phrase and show patience, they are those who will be truly guided.