Sayyiduna Anas (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) kept reciting the qunut of calamity until he passed away; Sayyiduna Abu Bakr also kept reciting it until he died, and Sayyiduna Umar also kept reciting it until he died.
Imam al-Bazzar recorded it, and its narrators have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2836