Salman al-Ouda
In Ali Soufan's book "The Black Banners", he explains the title by noting that quotes from various Hadiths regarding "Black Banners" of a "new army" taking over Khorasan have some kind of prophetic significance with many modern adherents of extremist jihadism. He notes that it is "not a coincidence" that Osama bin Laden made al-Qaeda's flag black. Soufan also notes that there is debate about whether the prophet Mohammed actually spoke some of the quoted Hadiths (such as one attributed to Abu Hurairah). He also notes that Sheikh Salman al-Ouda has said the Black Banner hadiths are not able to be authenticated.