«وَلَوْ دَامَتِ الدَّوْلَاتُ كَانُوا كَغَيْرِهِمْ ...»
If states had endured permanently, they would have been like others ...
The poetic thought contrasts the failure of earlier realms to endure with an idealized claim concerning the praised subject. Law introduces an imagined permanence against the experienced instability of dynasties.
The rhetorical mechanism is the central lesson: the poet adopts an unrealized condition to intensify praise and contrast. This is poetic reasoning and hyperbole, not a universally valid mathematical proof.