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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
muslim:1774a – Yūsuf b. Ḥammād al-Maʿnī > ʿAbd al-Aʿlá > Saʿīd > Qatādah > Anas

It has been narrated on the authority of Anas that the Prophet of Allah ﷺ wrote to Chosroes (King of Persia), Caesar (Emperor of Rome), Negus (King of Abyssinia) and every (other) despot inviting them to Allah, the Exalted. And this Negus was not the one for whom the Messenger of Allah ﷺ had said the funeral prayers.  

مسلم:١٧٧٤a – حَدَّثَنِي يُوسُفُ بْنُ حَمَّادٍ الْمَعْنِيُّ حَدَّثَنَا عَبْدُ الأَعْلَى عَنْ سَعِيدٍ عَنْ قَتَادَةَ عَنْ أَنَسٍ

أَنَّ نَبِيَّ اللَّهِ ﷺ كَتَبَ إِلَى كِسْرَى وَإِلَى قَيْصَرَ وَإِلَى النَّجَاشِيِّ وَإِلَى كُلِّ جَبَّارٍ يَدْعُوهُمْ إِلَى اللَّهِ تَعَالَى وَلَيْسَ بِالنَّجَاشِيِّ الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ ﷺ  

See similar narrations below:

Collected by Tirmidhī, Nasāʾī's Kubrá
tirmidhi:2716 – Yūsuf b. Ḥammād al-Baṣrī > ʿAbd al-Aʿlá > Saʿīd > Qatādah > Anas b. Mālik

"Before he died, the Messenger of Allah ﷺ had written to Kisra, Ceasar, An-Najashi, and to every tyrant calling them to Allah. This An-Najashi is not the one that the Prophet ﷺ performed to the funeral Salat for."  

Abū ʿĪsá said that this Ḥadīth is Ḥasan-Ṣaḥīḥ-Gharīb.
الترمذي:٢٧١٦ – حَدَّثَنَا يُوسُفُ بْنُ حَمَّادٍ الْبَصْرِيُّ حَدَّثَنَا عَبْدُ الأَعْلَى عَنْ سَعِيدٍ عَنْ قَتَادَةَ عَنْ أَنَسِ بْنِ مَالِكٍ

أَنَّ رَسُولَ اللَّهِ ﷺ كَتَبَ قَبْلَ مَوْتِهِ إِلَى كِسْرَى وَإِلَى قَيْصَرَ وَإِلَى النَّجَاشِيِّ وَإِلَى كُلِّ جَبَّارٍ يَدْعُوهُمْ إِلَى اللَّهِ وَلَيْسَ بِالنَّجَاشِيِّ الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ ﷺ  

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ
nasai-kubra:8796 – Yūsuf b. Ḥammād > ʿAbd al-Aʿlá > Saʿīd > Qatādah > Anas

"Before he died, the Messenger of Allah ﷺ had written to Kisra, Ceasar, An-Najashi, and to every tyrant calling them to Allah. This An-Najashi is not the one that the Prophet ﷺ performed to the funeral Salat for." (Using translation from Tirmidhī 2716)  

الكبرى للنسائي:٨٧٩٦ – أَخْبَرَنَا يُوسُفُ بْنُ حَمَّادٍ قَالَ حَدَّثَنَا عَبْدُ الْأَعْلَى عَنْ سَعِيدٍ عَنْ قَتَادَةَ عَنْ أَنَسٍ

أَنَّ رَسُولَ اللهِ ﷺ كَتَبَ قَبْلَ مَوْتِهِ إِلَى كِسْرَى وَإِلَى قَيْصَرَ وَإِلَى النَّجَاشِيِّ وَإِلَى كُلِّ جُبَارٍ يَدْعُوهُمْ إِلَى اللهِ تَعَالَى لَيْسَ النَّجَاشِيُّ الَّذِي صَلَّى عَلَيْهِ رَسُولُ اللهِ ﷺ