Muwatta Malik · Hadith 1822

وَحَدَّثَنِي مَالِكٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ أَبِيهِ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، دَخَلَ عَلَى أَبِي بَكْرٍ الصِّدِّيقِ وَهُوَ يَجْبِذُ لِسَانَهُ فَقَالَ لَهُ عُمَرُ مَهْ غَفَرَ اللَّهُ لَكَ ‏.‏ فَقَالَ أَبُو بَكْرٍ إِنَّ هَذَا أَوْرَدَنِي الْمَوَارِدَ ‏.‏

Malik related to me from Zayd ibn Aslam from his father that Umar ibn al-Khattab came upon Abu Bakr as-Siddiq pulling his tongue. Umar said to him, "Stop, may Allah forgive you!" Abu Bakr replied, "This has brought me to dangerous places

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).