That when his grandfather, Hazn visited the Prophet ﷺ the Prophet ﷺ said (to him), "What is your name?" He said, "My name is Hazn." The Prophet ﷺ said, " But you are Sahl." He said, "I will not change my name with which my father named me." Ibn Al-Musaiyab added: So we have had roughness (in character) ever since.
فَحَدَّثَنِي أَنَّ جَدَّهُ حَزْنًا قَدِمَ عَلَى النَّبِيِّ ﷺ فَقَالَ مَا اسْمُكَ قَالَ اسْمِي حَزْنٌ قَالَ بَلْ أَنْتَ سَهْلٌ قَالَ مَا أَنَا بِمُغَيِّرٍ اسْمًا سَمَّانِيهِ أَبِي قَالَ ابْنُ الْمُسَيَّبِ فَمَا زَالَتْ فِينَا الْحُزُونَةُ بَعْدُ