Sahih Muslim 2813
Sahih Muslim · Book 52: Characteristics of the Day of Judgment, Paradise, and Hell · The Mischief Of The Shaitan And How He Sends His Troops To Tempt People, And With Every Person There Is A Qarin (Companion From Among The Jinn)
Jabir reported that Allah's Apostle (may peace be upqn him) said:
حَدَّثَنِي سَلَمَةُ بْنُ شَبِيبٍ ، حَدَّثَنَا الْحَسَنُ بْنُ أَعْيَنَ ، حَدَّثَنَا مَعْقِلٌ ، عَنْ أَبِي الزُّبَيْرِ ، عَنْ جَابِرٍ ، أَنَّهُ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " يَبْعَثُ الشَّيْطَانُ سَرَايَاهُ فَيَفْتِنُونَ النَّاسَ فَأَعْظَمُهُمْ عِنْدَهُ مَنْزِلَةً أَعْظَمُهُمْ فِتْنَةً " .
The Satan sends detachments of his own in order to put people to trial and the highest in rank, in his eyes, is one who is most notorious in sowing the seed of dissension.