Mishkat al-Masabih 2 Knowledge كتاب العلم 43

وَعَنْهُ فِيمَا أَعْلَمُ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ اللَّهَ عَزَّ وَجَلَّ يَبْعَثُ لِهَذِهِ الْأُمَّةِ عَلَى رَأْسِ كُلِّ مِائَةٍ سَنَةٍ مَنْ يُجَدِّدُ لَهَا دِينَهَا» . رَوَاهُ أَبُو دَاوُد

He also reported among the material he knew to come from God’s messenger that he said, “At the beginning of every century God will send one who will renew its religion for this people.” Abu Dawud transmitted it.