That he had long thick hair. "He asked the Prophet (about it) and he told him to take care of it and comb it every day."
كَانَتْ لَهُ جُمَّةٌ ضَخْمَةٌ فَسَأَلَ النَّبِيَّ ﷺ فَأَمَرَهُ أَنْ يُحْسِنَ إِلَيْهَا وَأَنْ يَتَرَجَّلَ كُلَّ يَوْمٍ
[Machine] He had a massive camel, so he asked the Prophet ﷺ for advice. The Prophet ﷺ commanded him to treat her kindly and to ride her every day. Abu Abdullah said, "And this is the closest to the correct answer, and Allah knows best."
كَانَتْ لَهُ جُمَّةٌ ضَخْمَةٌ فَسَأَلَ النَّبِيَّ ﷺ فَأَمَرَهُ أَنْ يُحْسِنَ إِلَيْهَا وَأَنْ يَتَرَجَّلَ كُلَّ يَوْمٍ قَالَ أَبُو عَبْدِ الرَّحْمَنِ «وَهَذَا أَشْبَهُ بِالصَّوَابِ وَاللهُ أَعْلَمُ»