When the Messenger of Allah ﷺ took a bath because of sexual intercourse, he poured three handfuls of water upon his head. Hasan b. Muhammad said to him (the narrator): My hair is thick. Upon this Jabir observed. I said to him: O son of my brother, the hair of the Messenger of Allah ﷺ was thicker than your hair and these were more fine (than yours). (Using translation from Muslim 329)
كَانَ رَسُولُ اللهِ ﷺ إِذَا اغْتَسَلَ مِنْ جَنَابَةٍ صَبَّ عَلَى رَأْسِهِ ثَلَاثَ حَفَنَاتٍ مِنْ مَاءٍ فَقَالَ الْحَسَنُ بْنُ مُحَمَّدٍ إِنَّ شَعْرِي كَثِيرٌ قَالَ جَابِرٌ فَقُلْتُ لَهُ يَا ابْنَ أَخِي كَانَ شَعْرُ رَسُولِ اللهِ ﷺ أَكْثَرَ مِنْ شَعْرِكَ وَأَطْيَبَ