Sunan Abi Dawud 1445
سنن أبي داود#1445Sahihحَدَّثَنَا أَبُو الْوَلِيدِ الطَّيَالِسِيُّ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ أَنَسِ بْنِ سِيرِينَ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَنَتَ شَهْرًا ثُمَّ تَرَكَهُ .
Anas b. Malik said:The Prophet (ﷺ) recited the supplication for a month (in prayer) and then gave it up
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-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (677)
In-book reference: 8:30