Abdullah bin Umar narrated that the Messenger of Allah صلى الله عليه وسلم said, “The fitnah of Al-Ahlas (continuous calamity) is mass desertion and war.
Then, the fitnah of As-Sarraa [meaning ‘the rich’, when some rich people use their money to hire others to fight for them] will start from under the feet of a man who claims that he is of me (of my descendants). However, he is not of me, for my loyal friends are the ones who have taqwa.
Afterwards, people will unite around a man whose reign is unstable. Then, the fitnah of Ad-Duhaymaa [it is called ‘dark and black fitnah’ because of its enormity] (will start) and will not leave any member of this nation without severely touching him. When it is thought that its time has come to an end, it will be lengthened. Meanwhile (during this fitnah), a man will wake up as a believer and will meet the night as a disbeliever, until people divide into two camps: A camp of belief that contains no hypocrisy, and a camp of hypocrisy that contains no belief. If this happens, then await the Dajjal on that day or the next.”
Ahmad, Abu Dawood and al-Hakim, Mishkatul-Masabih, vol. 4, no. 5403