«لِتُنْذِرَ أُمَّ الْقُرَىٰ وَمَنْ حَوْلَهَا وَتُنْذِرَ يَوْمَ الْجَمْعِ لَا رَيْبَ فِيهِ»
“So that you may warn the Mother of Cities and those around it, and warn of the Day of Gathering, about which there is no doubt.” (al-Shūrā 42:7, excerpt)
The warning verb is repeated with a shift in what follows it. First the addressees are named; then the Day of Gathering is the matter about which they are warned.
These are complementary aspects of one prophetic warning. The parallel formulation connects the audience to the ultimate subject of the warning, making the purpose and the audience equally clear.