What does “laysa al-karīm ʿalā al-qanā bi-muḥarram” mean in context?

ʿAntarah ibn Shaddād: Cavalry Witnesses, Courage, Restraint and Duels (verses 43–56)

• A noble never sees battle
• Spears are meant only for commoners
• Even nobles are not immune to a spear
• Battle always ends in peace