Hadithcore
Sunan Abi Dawud, 538
hasan· Al-Albani

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).

حَدَّثَنَا 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 ‏.‏

References2 variants
In-Book Reference
Book 2, Hadith 148
English Reference
Book 2, Hadith 538