30:59
كَذَٰلِكَ يَطْبَعُ ٱللَّهُ عَلَىٰ قُلُوبِ ٱلَّذِينَ لَا يَعْلَمُونَ
kadhālika yaṭbaʿu l-lahu ʿalā qulūbi alladhīna lā yaʿlamūna
In this way God seals the hearts of those who do not know,
Thus does Allâh seal up the hearts of those who know not [the proofs and evidence of the Oneness of Allâh i.e. those who try not to understand true facts that which you (Muhammad صلى الله عليه وسلم) have brought to them].