What argument does the poet draw from waladnā ʿAmran ibn Umm Unās?

al-Ḥārith ibn Ḥillizah: Ḥujr, Royal Kinship and the Dhū al-Majāz Covenant (verses 56–67)

• A claim of kinship with the royal family
• A geographic division of rivers
• Construction of a new fort
• A declaration that he is king