﴿ إِنَّمَا ذَٰلِكُمُ ٱلشَّيْطَٰنُ يُخَوِّفُ أَوْلِيَآءَهُۥ فَلَا تَخَافُوهُمْ وَخَافُونِ إِن كُنتُم مُّؤْمِنِينَ ﴾

“It is but Satan who instils [into you] fear of his allies: so fear them not, but fear Me, if you are [truly] believers!”

(It is only the devil) the one who was scaring you with ways of the devil, i.e. Nu'aym Ibn Mas'ud. Allah called him a devil because he was a follower of Satan and his whisperings (who would make (men) fear his partisans) He says: he makes you fear his partisans: the unbelievers. (Fear them not) in your sortie; (fear Me) if you stay back, (if you are true believers) if you believe in His bringing back the dead to life.