Abdul-Rahman bin Abdul-Qari reported,

I went out one night during Ramadan with Umar bin Khattab to the mosque, and there we found the people scattered in separate groups. One man would be praying alone, while another would be praying with a small group following him.Umar said, "I think it would be better if I gathered all these people behind a single reciter."He then resolved to do so and gathered them behind Ubayy bin Kaab.Then I went out with him on another night, and the people were praying behind their reciter.Umar said, "What an excellent innovation this is. But the prayer they sleep through is better than the one they stand for," meaning the latter part of the night, since the people were standing in prayer at its beginning.

وعن ابن شهاب عن عروة بن الزبير

عن عبد الرحمن بن عبد القاري أنه قال

خرجت مع عمر بن الخطاب رضي الله عنه ليلة في رمضان إلى المسجد فإذا الناس أوزاع متفرقون يصلي الرجل لنفسه ويصلي الرجل فيصلي بصلاته الرهط فقال عمر إني أرى لو جمعت هؤلاء على قارئ واحد لكان أمثل ثم عزم فجمعهم على أبي بن كعب ثم خرجت معه ليلة أخرى والناس يصلون بصلاة قارئهم قال عمر نعم البدعة هذه والتي ينامون عنها أفضل من التي يقومون يريد آخر الليل وكان الناس يقومون أوله