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Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
bayhaqi:4793 – Abū Saʿīd Yaḥyá b. Muḥammad b. Yaḥyá al-Isfarāyīnī > Abū Baḥr al-Barbahārī > Bishr b. Mūsá > al-Ḥumaydī > Sufyān > ʿUbaydullāh b. Abū Yazīd > Kurayb

[Machine] I saw Muawiyah praying the night prayer, then he performed an additional rak'ah (unit of prayer). I mentioned this to Ibn Abbas and he said, "He did the correct thing."  

البيهقي:٤٧٩٣ – وَأَخْبَرَنَا أَبُو سَعِيدٍ يَحْيَى بْنُ مُحَمَّدِ بْنِ يَحْيَى الْإِسْفَرَايِينِيُّ ثنا أَبُو بَحْرٍ الْبَرْبَهَارِيُّ ثنا بِشْرُ بْنُ مُوسَى ثنا الْحُمَيْدِيُّ ثنا سُفْيَانُ حَدَّثَنِي عُبَيْدُ اللهِ بْنُ أَبِي يَزِيدَ أَخْبَرَنِي كُرَيْبٌ قَالَ

رَأَيْتُ مُعَاوِيَةَ صَلَّى الْعِشَاءَ ثُمَّ أَوْتَرَ بِرَكْعَةٍ فَذَكَرْتُ ذَلِكَ لِابْنِ عَبَّاسٍ فَقَالَ أَصَابَ