Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 56

وَعَنْ جَابِرِ بْنِ سَمُرَةَ قَالَ: كَانَ فِي سَاقَيْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ حُمُوشَةٌ وَكَانَ لَا يَضْحَكُ إِلَّا تَبَسُّمًا وَكُنْتُ إِذَا نَظَرْتُ إِلَيْهِ قُلْتُ: أَكْحَلُ الْعَيْنَيْنِ وَلَيْسَ بأكحل. رَوَاهُ التِّرْمِذِيّ

Jabir b. Samura said: God’s messenger’s legs were slender, his laughter was no more than a smile, and when I looked at him, I thought that there was collyrium in his eyes, but there was not. Tirmidhi transmitted it.