"And so that you may know that the promise of Allah is true," meaning: that which was cast into her heart. "But most of them do not know," meaning: their collective group.
Surah Al-Qasas (Verse 14 - Verse 19).
﴿وَلِتَعْلَمَ أَنَّ وَعْدَ اللَّهِ حَقٌّ﴾ يَعْنِي: الَّذِي قُذِفَ فِي قَلْبِهَا ﴿وَلَكِن أَكْثَرهم لَا يعلمُونَ﴾ يَعْنِي: جَمَاعَتهمْ.
سُورَة الْقَصَص من (آيَة ١٤ - آيَة ١٩).