Fortress of the Muslim (Hisn al-Muslim)
حصن المسلم
(39) Chapter: When being afraid of a group of people
(39) ما يقول من خاف قوماً
Hisn al-Muslim 132 
Allāhummak-finīhim bimā shi't. O Allah, suffice (i.e. protect) me against them however You wish. Reference: Muslim 4/2300.
اللَّهُمَّ اكْفِنِيهِم بمَا شِئْت
Reference : Hisn al-Muslim 132