Mikeal Parsons' commentary on the Book of Acts in the Paideia series. Periodically Parsons will point out rhetorical figures of speech. This one comes from Paul's Areopagus speech in Acts 17:22-31.
In this passage, Luke inflects the word God (Theos) in four cases. Grammatical inflection, sometimes called polyptoton or klisis, involves inflecting the author's main subject in multiple cases. In this passage, theos is used five times and in four cases: 17:23 dative, 17:24 nominative, 17:27 accusative, 17:29 genitive, and 17:30 nominative. Inflection serves both to show the author's skill in composition and to signal to the audience to the main subject. Unfortunately, polyptoton is a figure that is impossible to carry over in translation.
Source: Mikeal C. Parsons, Acts, Paideia (Grand Rapids: Baker Academic, 2008), 249.