Narrated Abu Hurairah: The Messenger of Allah (ﷺ) came out and saw that the people were praying during (the night of) Ramadan in the corner of the mosque. He asked: Who are these people ? It was said to him that those were people who had not learnt Quran. But Ubayy b. Ka'b is praying and they would pray behind him. The Prophet (ﷺ) said: They did right and it is good what they did. Abu Dawud said: This tradition is not strong, the narrator Muslim b. Khalid is weak

English translation · Sunan Abu Dawud