Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 71

وَعَنْهُ قَالَ: لَمْ يَكُنْ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَاحِشًا وَلَا لَعَّانًا وَلَا سَبَّابًا كَانَ يَقُولُ عِنْدَ الْمَعْتَبَةِ: «مَا لَهُ تربَ جَبينُه؟» . رَوَاهُ البُخَارِيّ

He said that God’s messenger was not unseemly in his language, or given to cursing or reviling. All he said when reproaching someone was, “What is the matter with him? May his forehead cleave to the dust!” Bukhari transmitted it.