The Prophet ﷺ led the dawn prayer and recited Surah ar-Rum, but his recitation became confused. When he finished praying, he said, "What is the matter with people who pray with us yet do not perform their purification properly? It is they who cause the Quran to become confused for us."
أخبرنا محمد بن بشار قال حدثنا عبد الرحمن قال أنبأنا سفيان عن عبد الملك بن عمير عن شبيب أبي روح
عن النبي ﷺ أنه صلى صلاة الصبح فقرأ الروم فالتبس عليه فلما صلى قال ما بال أقوام يصلون معنا لا يحسنون الطهور فإنما يلبس علينا القرآن أولئك
Sahih. Ahmad reported it (5:363) from the hadith of Sufyan Thawri, with this chain, and Shubah and Zaidah followed him in narrating it (Ahmad 3:471, 1/3, 5:368, 472), and the hadith is in al-Kubra, no. 1019.Abdul-Malik explicitly stated that he heard it directly, and Shabib is trustworthy. Sharik also narrated it from Abdul-Malik, from Abu Rawh Kalai, with this chain, explicitly stating that he heard it directly.