9:45
إِنَّمَا يَسْتَـْٔذِنُكَ ٱلَّذِينَ لَا يُؤْمِنُونَ بِٱللَّهِ وَٱلْيَوْمِ ٱلْـَٔاخِرِ وَٱرْتَابَتْ قُلُوبُهُمْ فَهُمْ فِى رَيْبِهِمْ يَتَرَدَّدُونَ
innamā yastadhinuka alladhīna lā yu'minūna bil-lahi wal-yawmi l-ākhiri wa-ir'tābat qulūbuhum fahum fī raybihim yataraddadūna
only those who do not have faith in God and the Last Day ask your permission to stay at home: they have doubt in their hearts and so they waver.
It is only those who believe not in Allâh and the Last Day and whose hearts are in doubt that ask your leave (to be exempted from Jihâd). So in their doubts they waver.