Not graded
Riyad as-Salihin 695
Whenever the Prophet (ﷺ) 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].
عن أنس رضي الله عنه أن النبى صلى الله عليه وسلم كان إذا تكلم بكلمة أعادها ثلاثاً حتى تفهم عنه، وإذا أتى على قومٍ فسلم عليهم سلم عليهم ثلاثاً. ((رواه البخاري)).