Sunan Abi Dawud 538
سنن أبي داود#538Hasanحَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا أَبُو يَحْيَى الْقَتَّاتُ، عَنْ مُجَاهِدٍ، قَالَ كُنْتُ مَعَ ابْنِ عُمَرَ فَثَوَّبَ رَجُلٌ فِي الظُّهْرِ أَوِ الْعَصْرِ قَالَ اخْرُجْ بِنَا فَإِنَّ هَذِهِ بِدْعَةٌ .
Narrated Abdullah ibn Umar: Mujahid reported: I was in the company of Ibn Umar. A person invited the people for the noon or afternoon prayer (after the adhan had been called). He said: Go out with us (from this mosque) because this is an innovation (in religion)
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:
In-book reference: 2:148