Sunan Abi Dawud 1512
سنن أبي داود#1512Sahihحَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا شُعْبَةُ، عَنْ عَاصِمٍ الأَحْوَلِ، وَخَالِدٍ الْحَذَّاءِ، عَنْ عَبْدِ اللَّهِ بْنِ الْحَارِثِ، عَنْ عَائِشَةَ، رضى الله عنها أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ إِذَا سَلَّمَ قَالَ " اللَّهُمَّ أَنْتَ السَّلاَمُ وَمِنْكَ السَّلاَمُ تَبَارَكْتَ يَا ذَا الْجَلاَلِ وَالإِكْرَامِ " .
Aishah said:When the Prophet (ﷺ) uttered taslim, he used to say: "O Allah, You are As-Salam, and from you is As-Salam. You are blessed, O One of Magnificence and Generosity
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 8:97