17:45
وَإِذَا قَرَأْتَ ٱلْقُرْءَانَ جَعَلْنَا بَيْنَكَ وَبَيْنَ ٱلَّذِينَ لَا يُؤْمِنُونَ بِٱلْـَٔاخِرَةِ حِجَابًا مَّسْتُورًا
wa-idhā qarata l-qur'āna jaʿalnā baynaka wabayna alladhīna lā yu'minūna bil-ākhirati ḥijāban mastūran
[Prophet], when you recite the Quran, We put an invisible barrier between you and those who do not believe in the life to come.
And when you (Muhammad صلى الله عليه و سلم) recite the Qur’ân, We put between you and those who believe not in the Hereafter, an invisible veil (or screen their hearts, so they hear or understand it not).