He said: "And We wronged them not," meaning: the disbelievers of all nations, such that We would punish them in the Hereafter without a sin having been committed, "but they were themselves the wrongdoers" to their own selves through their disbelief.
Muhammad said: "They are the wrongdoers"—the word "they" (hum) here is an expletive (silah); thus, it has no place in grammatical parsing.
قَالَ: ﴿وَمَا ظَلَمْنَاهُمْ﴾ يَعْنِي: كفار الْأُمَم كلهَا؛ فنعذبهم فِي الْآخِرَة بِغَيْر ذَنْب ﴿وَلَكِنْ كَانُوا هم الظَّالِمين﴾ لأَنْفُسِهِمْ بكفرهم.
قَالَ محمدٌ: ﴿هُمُ الظَّالِمُونَ﴾ هم هَا هُنَا صلَة؛ فَلَا مَوضِع لَهَا فِي الْإِعْرَاب.