"Thus does Allah seal the hearts of those who do not know," meaning: those who meet Allah with their polytheism.
﴿كَذَلِكَ يَطْبَعُ اللَّهُ عَلَى قُلُوبِ الَّذين لَا يعلمُونَ﴾ يَعْنِي: الَّذِينَ يَلْقَوْنَ اللَّهَ بِشِرْكِهِمْ