The people were reciting the Quran aloud behind the Messenger of Allah ﷺ, so the Messenger of Allah ﷺ said to them, "You have confused the Quran for me."
كان الناس يجهرون بالقرآن خلف رسول الله ﷺ فقال لهم رسول الله ﷺ: خلطتم علي القرآن.
No references are available.
Narrated by Ahmad (4309), Abu Yaala in Maqsad Ali (269), Bazzar in Kashf Astar (488), and Bukhari in Juz Qira (p. 126), all of them through Yunus bin Abu Ishaq, from Abu Ishaq, from Abu Ahwas, from Abdullah, who mentioned it. The wording given is that of Abu Yaala, and Bukhari's wording is similar.Its chain of transmission is hasan because of Yunus bin Abu Ishaq, since there is disagreement about him. Imam Ahmad said, "His hadith is inconsistent." Ibn Main deemed him trustworthy. Abu Hatim said, "He was truthful, but his hadith cannot be relied upon as proof." Nasai said, "There is nothing wrong with him." The summary, as Hafiz said in Taqrib, is "Truthful, but errs slightly."I say, this is as he said, except that he did not err in this hadith, because it agrees with what the trustworthy narrators reported about people reciting aloud behind the Messenger of Allah ﷺ. He only became confused regarding the reciting aloud, for they were forbidden from doing that, and were permitted instead to recite silently to themselves. This is the heading Imam Bukhari used in Juz Qira, saying, "Chapter: one should not recite aloud behind the imam."