Musnad Ahmad Hadith 22452

It is narrated from Thawban (may Allah be pleased with him) that the Holy Prophet (ﷺ) said: Allah Almighty gathered the entire earth for me, so I saw its east and its west, and the rule of my Ummah will reach as far as the area that was gathered and shown to me. And I was given two treasures, the red and the white. And I requested my Lord for my Ummah that He should not destroy them by a general famine, and that He should not impose upon them an external enemy who would massacre them. So my Lord said: O Muhammad! No one can overturn what I have decreed. I have accepted your prayer for your Ummah that I will not destroy them by a general famine, and I will not impose upon them an external enemy who will commit great slaughter among them, even if their enemies gather against them from all corners of the world, until they themselves begin to destroy one another. And when the sword is placed among my Ummah, it will not be lifted from them until the Day of Resurrection. And the Hour will not be established until some tribes of my Ummah join the polytheists, and until some tribes of my Ummah begin to worship idols.