Answered by Sidi Moustafa Elqabbany
Can you please tell me which, if any, movements are allowed during prayer and do not invalidate the prayer? In particular, I am asking about re-adjusting the scarf for women (in case it is falling off or hair is showing), scratching the nose or face, and also what should be done if we need to yawn or sneeze.
Your question touches on some of the invalidators of prayer. These rulings are the same for women and men.
Regarding movements in prayer, this has already been addressed here:
Etiquette for praying with small children (Part 2)
(Note: The above discussion is not a thoroughly complete coverage on issues of which movements invalidate prayer, but it is sufficient for most practical purposes.)
In summary, if you can adjust your scarf, scratch your nose or face, or cover your mouth while yawning or sneezing with one or two consecutive movements of heavy limbs, then the prayer is valid. Otherwise, it is invalid. Note that the fingers are considered light limbs, so no amount of moving them invalidates the prayer, unless done in play.
As for a woman’s hair, or any other part of one’s `awra (nakedness), becoming exposed during prayer, it invalidates the prayer. Thus, adjusting one’s scarf because of hair being exposed isn’t something one would normally do in prayer. (The exception to this is when wind is the cause of the `awra being exposed and it is immediately covered.) As long as you are certain that you covered your `awra before prayer, you should maintain this certainty unless you’re sure it has become uncovered.
And Allah the Exalted knows best.
Moustafa Elqabbany