﴿ أَلَمْ تَعْلَمْ أَنَّ ٱللَّهَ لَهُۥ مُلْكُ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ يُعَذِّبُ مَن يَشَآءُ وَيَغْفِرُ لِمَن يَشَآءُ ۗ وَٱللَّهُ عَلَىٰ كُلِّ شَىْءٍۢ قَدِيرٌۭ ﴾

“Dost thou not know that God's is the dominion over the heavens and the earth? He chastises whom He wills, and He forgives whom He wills: for God has the power to will anything.”

Do you not know the interrogative here is meant as an affirmative that to God belongs the kingdom of the heavens and the earth? He chastises him for whom He wills chastisement for and forgives him for whom He wills forgiveness and God has power over all things including chastising and forgiving.