وَاللَّهُ الَّذِي أَرْسَلَ الرِّيَاحَ فَتُثِيرُ سَحَابًا فَسُقْنَاهُ
God is the One who sends the winds; they stir clouds, then We drive them onward.
«اللَّهُ» and «أَرْسَلَ» refer to God in the third person; «فَسُقْنَاهُ» introduces the first-person plural. Divine agency is now narrated from a directly speaking perspective.
This is third person → first person. Where the passage also contains changes of tense, person shift and tense shift must be analyzed separately rather than attributed to a single mechanism.