Mishkat al-Masabih
Mishkat al-Masabih 5798
The Prophet's Names and Characteristics - Section 3
Arabic hadith text
وَعَنْ كَعْبِ بْنِ مَالِكٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا سُرَّ اسْتَنَارَ وَجْهُهُ حَتَّى كَأَنَّ وَجْهَهُ قِطْعَةُ قَمَرٍ وَكُنَّا نَعْرِفُ ذَلِكَ. مُتَّفَقٌ عَلَيْهِ
Translation
Ka'b b. Malik said
When God's messenger was pleased his face lit up so that it looked like a bit of a moon, and we were familiar with that. (Bukhari and Muslim.)