"Thus do We relate to you of the accounts of what has passed"—meaning: of the reports of what has gone by. "And We have given you"—meaning: We have bestowed upon you—"from Us"—meaning: from Our presence—"a Reminder," meaning: the Quran.
﴿كَذَلِكَ نَقُصُّ عَلَيْكَ مِنْ أَنْبَاءِ مَا قد سبق﴾ أَيْ: مِنْ أَخْبَارِ مَا قَدْ مضى ﴿وَقد آتيناك﴾ أعطيناك ﴿من لدنا﴾ من عندنَا ﴿ذكرا﴾ يَعْنِي: الْقُرْآن