يَطْبَعُ الْأَسْجَاعَ بِجَوَاهِرِ لَفْظِهِ
He shaped ornate rhyming prose with the jewels of his words.
Yaṭbaʿu normally suggests impressing, stamping or shaping. In this context it portrays the crafted arrangement of rhymed prose, while jawāhir likens polished words to precious stones. Craft, jewels and speech converge in one sentence.
The subject is the orator, al-asjāʿ is the object, and the prepositional phrase describes the instrument or manner. The rhetorical effect arises from assigning material craftsmanship to verbal composition. Name the semantic transfer, not merely its attractive vocabulary.