Question Summary:
What does Islam say about Deja vu?

Question Detail:

 
What does Islam say about deja vu. I sometimes feel that an incident has occured before.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykumwa-rahmatullāhiwa-barakātuh.
Déjà vu is a recollection of an incident of the past. Recollection of past incidents are natural. 
And Allah Ta’āla Knows Best
Zakir Husain
Student DarulIftaa
Michigan, U.S.A
Checked and Approved by,
Mufti Ebrāhīm Desai.
Déjà vu:French pronunciation: ​[de.ʒa.vy]) from French, literally "already seen", is the phenomenon of having the strong sensation that an event or experience currently being experienced has already been experienced in the past. Déjà vu is a feeling of familiarity, and Déjà  déjà vécu (the feeling of having "already lived through" something) is a feeling of recollection.
https://en.wikipedia.org/wiki/D%C3%A9j%C3%A0_vu