«وَخَلِّدُوهَا بِبُطُونِ الْأَوْرَاقِ»
And preserve it for posterity within the pages.
Khallidū means to make lasting. Buṭūn al-awrāq literally means “the bellies of the sheets,” a vivid way to mean committing the account to writing.
A bodily image is transferred to inanimate paper, giving the act of writing imaginative force. The speaker wants a passing spoken story to become a lasting written record.
«فَمَا سُيِّرَ مِثْلُهَا فِي الْآفَاقِ»
Nothing like it has circulated across the horizons. Suyyira is past passive, and the claim is rhetorical hyperbole.