عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «بَلِّغُوا عَنِّي وَلَوْ آيَةً وَحَدِّثُوا عَنْ بَنِي إِسْرَائِيلَ وَلَا حَرَجَ وَمَنْ كَذَبَ عَلَيَّ مُتَعَمِّدًا فَلْيَتَبَوَّأْ مَقْعَدَهُ مِنَ النَّارِ» . رَوَاهُ البُخَارِيّ

Anas said that when the Prophet made a statement he repeated itthree times so that it would be understood, and that when he met a company and gave them a salutation he did it three times. Bukharitransmitted it.