Jami` at-Tirmidhi 2928
جامع الترمذي#2928Da'ifNarrated Anas:that the Prophet (ﷺ), Abu Bakr, and 'Umar - and I think he said - and 'Uthman would recite: "Maaliki Yawmid-Din (1:)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirDaif Isnaad
Al-AlbaniDaif Isnaad
Zubair Ali ZaiDaif
In-book reference: 46:2