أَيُّهَا النَّاطِقُ الْمُبَلِّغُ عَنَّا عِنْدَ عَمْرٍو وَهَلْ لِذَاكَ انْتِهَاءُ
Meaning: O bearer of reports about us to ʿAmr: will this activity of yours ever come to an end?
Al-nāṭiq is the speaker, while al-muballigh is the carrier of a report. Together the two participles stress both speaking and transmitting claims to the royal court.
The question wa-hal li-dhāka intihāʾ is less an innocent request for information than a protest against continuing accusations. The reference to ʿAmr is to ʿAmr ibn Hind, before whom the tribal case is being made.