Imam Al-Nawawi’s Riyad-us-Saliheen
Clarity of Discourse
696. Anas (May Allah be pleased with him) reported: Whenever the Prophet (sallallaahu alayhi wa sallam) said something, he would repeat his words thrice so that the meanings would be understood fully; and whenever he came upon a group of people, he would greet them, and he would repeat salutation thrice.
[Al-Bukhari and Muslim].
697. `Aishah (May Allah be pleased with her) reported: the speech of Messenger of Allah (sallallaahu alayhi wa sallam) was so clear that all those who listened to it would understand it.