Sura al-Tawbah 9:45

إِنَّمَا يَسْتَـْٔذِنُكَ ٱلَّذِينَ لَا يُؤْمِنُونَ بِٱللَّـهِ وَٱلْيَوْمِ ٱلْأَخِرِ وَٱرْتَابَتْ قُلُوبُهُمْ فَهُمْ فِى رَيْبِهِمْ يَتَرَدَّدُونَ

innamā yastaʾdhinuka lladhīna lā yuʾminūna billāhi wa-l-yawmi l-akhiri wa-irtābat qulūbuhum fa-hum fī raybihim yataraddadūna

Only those ask thee for exemption who believe not in Allah and the Last Day, and whose hearts are in doubt, so that they are tossed in their doubts to and fro.