It is narrated from Sayyiduna al-Mustawrid bin Shaddad (may Allah be pleased with him) that he narrated this hadith from the Prophet (peace and blessings be upon him): He (peace and blessings be upon him) said: "Every nation has an appointed term, and the term of the Ummah of Muhammad (peace and blessings be upon him) is one hundred years." He said: "So when the hundred years have passed, there will come to it what Allah has promised it."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17860