A man came and said, "Allah, forgive me and Muhammad, and do not let anyone share with us in Your mercy."The Prophet ﷺ asked, "Who said that?"The man replied, "I did."The Prophet ﷺ said, "You have shut them out from many people."
أن رجلا جاء فقال: اللهم اغفر لي ولمحمد، ولا تشرك في رحمتك إيانا أحدا فقال النبي ﷺ: من قائلها؟ فقال الرجل: أنا. فقال النبي ﷺ: لقد حجبتهن عن ناس كثير.
Ahmad (6590) narrated it, and this is his wording, as did Bukhari in Adab al-Mufrad (626), and Ibn Hibban (986) graded it sahih. All of them narrated it through Hammad bin Salama, from Ata bin Saaib, from his father, from Abdullah bin Amr, who related it.Its chain of transmission is sahih. Saaib is reliable, the leading scholars affirmed his reliability, though he became confused in memory late in his life. However, Hammad bin Salama's narration from him predates that confusion.As for Haythami, he said in Majma (10/150), "Ahmad and Tabarani narrated it in similar wording, and their chain of transmission is hasan."