Sunan Abi Dawud 1428
سنن أبي داود#1428Da'ifحَدَّثَنَا أَحْمَدُ بْنُ مُحَمَّدِ بْنِ حَنْبَلٍ، حَدَّثَنَا مُحَمَّدُ بْنُ بَكْرٍ، أَخْبَرَنَا هِشَامٌ، عَنْ مُحَمَّدٍ، عَنْ بَعْضِ، أَصْحَابِهِ أَنَّ أُبَىَّ بْنَ كَعْبٍ، أَمَّهُمْ - يَعْنِي فِي رَمَضَانَ - وَكَانَ يَقْنُتُ فِي النِّصْفِ الآخِرِ مِنْ رَمَضَانَ .
Muhammad reported on the authority of some of his teachers that Ubayy b. Ka'b led them in prayer during Ramadan. He used to recite the supplication (in the witr) during the second half of Ramadan
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniDaif
Muhammad Muhyi Al-Din Abdul HamidDaif
Zubair Ali ZaiDaif
In-book reference: 8:13