Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 88

وَعَنْ عَائِشَةَ قَالَتْ: مَا كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَسْرُدُ سَرْدَكُمْ هَذَا وَلَكِنَّهُ كَانَ يَتَكَلَّمُ بِكَلَامٍ بَيْنَهُ فَصْلٌ يَحْفَظُهُ من جَلَسَ إِلَيْهِ. رَوَاهُ التِّرْمِذِيّ

`A’isha said: God’s messenger did not go on talking rapidly as you do, but spaced out his words so that those who sat with him could remember them. Tirmidhi transmitted it.