Mughira b. Shu'ba wrote to Mu'awiya (it was Warrad who wrote this letter for him, i. e. Mughira): I heard the Messenger of Allah ﷺ saying:" When the salutation is pronounced." and the rest of the hadith is the same except this that he made no mention of:" He is Potent over everything."
سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ حِينَ سَلَّمَ بِمِثْلِ حَدِيثِهِمَا إِلاَّ قَوْلَهُ وَهُوَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ فَإِنَّهُ لَمْ يَذْكُرْ