In the Name of Allāh, the Ever Merciful, the Bestower of Mercy
Q: If after finishing the Zhuhr (Noon) Prayer, for example, I discovered that part of my hair was uncovered, should I repeat the Salah (Prayer) or should I repeat the last two Rak’ahs (units of Prayer) in which I discovered that my hair showed? May Allah reward you with the best!
A: This matter can be detailed as follows. If a few hairs become uncovered and you do not know about that until after finishing Salah, then there is nothing wrong and your Salah is valid. But if a large part of your head shows, then it is better to repeat the Salah to be on the safe side.
(Part No.7; Page No. 268)
Q: A female questioner from Jizan district says: When I was performing Sujud (prostration) in Zhuhr Prayer, my son uncovered my whole head by pulling the head cover, but I took it and put it immediately on my head and continued with the Salah? Is my Salah valid?
A: Yes, if you put on the head cover straightaway, then there is no problem and the Salah is valid, Al-hamdu lillah (All praise is due to Allah).
Source: Fatwas of Nur ‘ala Al-Darb, volume 7, Part No.7; Page No.268|Question no. 144|www.alifta.net