At-Tawbah 9:127

Wa-itha ma onzilat sooratunnathara baAAduhum ila baAAdinhal yarakum min ahadin thumma insarafoo sarafaAllahu quloobahum bi-annahum qawmun la yafqahoon

And whenever a sūrah is revealed, they look at each other, [as if saying], "Does anyone see you?" and then they dismiss themselves. Allāh has dismissed their hearts because they are a people who do not understand.

And when a Sūrah is sent down, they look at each other (as if saying): “Is there someone watching you?” Then they turn away. Allah has turned their hearts, because they are a people who do not understand.