Gheerah

From The Advice to the Women:

Jealousy (Gheerah) is of two types, praiseworthy and blameworthy. Praiseworthy jealousy is the type of jealousy that does not trangress the limits of Islaamic law. Blameworthy jealousy is the jealousy that trangresses beyond the limits of the Islaamic law. Therefore, if it transgresses Islaamic law then it is blameworthy because it incites the one who possesses this emotion to make accusations towards others and more specifically the accusations of the husbands towards their wives. 

Allah the Mighty and Majestic says: "Avoid (too) much assumption. Indeed some assumption is sinful" Surah Hujurat [49:12]. 

Aboo Hurayrah (radiAllaahu anh) said that the Messenger of Allah (sallAllaahu alayhi wa salam) said: "Beware of suspicion for indeed, suspicion is the most deceptive speech."