Sunan Abi Dawud 1549
سنن أبي داود#1549Sahihحَدَّثَنَا مُحَمَّدُ بْنُ الْمُتَوَكِّلِ، حَدَّثَنَا الْمُعْتَمِرُ، قَالَ قَالَ أَبُو الْمُعْتَمِرِ أُرَى أَنَّ أَنَسَ بْنَ مَالِكٍ، حَدَّثَنَا أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَقُولُ " اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ صَلاَةٍ لاَ تَنْفَعُ " . وَذَكَرَ دُعَاءً آخَرَ .
Anas bin Malik narrated that the Prophet (ﷺ) would say:"O Allah, I seek refuge in You from a prayer that is of no benefit
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 ZaiDaif
In-book reference: 8:134