Sahih Bukhari Volume 8, Book 80, Hadith Number 717.

Narrated By Abu Huraira: Allah’s Apostle said, ‘Beware of suspicion, for it is the worst of false tales and don’t look for the other’s faults and don’t spy and don’t hate each other, and don’t desert (cut your relations with) one another O Allah’s slaves, be brothers!” (See Hadith No. 90)