Narrated 'Urwah:
that 'Aishah said: "The Messenger of Allah (ﷺ) did not speak quickly like you do now, rather he would speak so clearly, unmistakably, that those who sat with him would memorize it." (ES)
English reference (ES): Vol. 1, Book 46, Hadith 3639 (ES)
Arabic reference (ES): Book 49, Hadith 4000 (ES)