Aqidah (Belief)

The Concept of the evil eye (nazar).

I would like to know the exact position of the evil eye (nazar) in Islam. If for example you praise the looks of a child and don’t say masha Allah, does that mean that something bad will happen to the child? If somebody is doing well in our community and then things go wrong then he must have nazar! Where do we stand on these issues and what should our yaqeen be. At the moment my belief is that it was meant to happen and if you try and please the Almighty then he will protect you regardless?