When is this going to stop

Khabbab came to the Prophet ﷺ, who was lying in the shade of the Ka'bah with his cloak folded under his head.

What Khabbab said was, in substance: will you not ask Allah to help us? Will you not pray for us?

It is worth registering how unusual that is. The early sources are not full of Companions complaining. This is a man who has been tortured over a period of years, who is enslaved, who has no family able to intervene, and who has come to the one person who might be able to do something, and asked him to do it.

He was not rebuked for asking.

The answer he was given was historical. Among those before you, a man would be seized and a pit dug for him and he would be put in it, and a saw would be brought and put on his head and he would be split in two; and he would be combed with iron combs, past the flesh to the bone — and none of that turned him from his religion.

Then: this matter will be completed, so that a rider will travel from one place to another fearing nothing but Allah — but you are being hasty.

Two things are being said at once, and both of them matter. The first is that the suffering is not a sign that something has gone wrong; people who were right have been through worse. The second is a promise about the future that is specific enough to be checked, and Khabbab lived to see it checked.

The report is in Sahih al-Bukhari.