"Their messengers said"—meaning: their messengers said to them: "Is there doubt about Allah, Creator of the heavens and the earth?"—meaning: their Originator. That is to say: there is no doubt about Him, and you acknowledge that He is the Creator of the heavens and the earth, so how can you worship anyone other than Him? "He invites you that He may forgive you of your sins"—meaning:
﴿قَالَت رسلهم﴾ أَيْ: قَالَتْ لَهُمْ رُسُلُهُمْ: ﴿أَفِي الله شكّ فاطر السَّمَاوَات وَالْأَرْض﴾ خَالِقِهِمَا؛ أَيْ: أَنَّهُ لَيْسَ فِيهِ شكٌّ، وَأَنْتُمْ تُقِرُّونَ أَنَّهُ خَالِقُ السَّمَوَات وَالأَرْضِ، فَكَيْفَ تَعْبُدُونَ غَيْرَهُ؟! ﴿يَدْعُوكُمْ ليغفر لكم من ذنوبكم﴾ أَيْ: