Does saying "Masha'Allah, La Quwwata illa Billah" (What Allah wills, there is no power except in Allah) or offering a blessing after a person or a material object has been afflicted by the evil eye (after fifteen minutes or an hour) remove the effect of the evil eye if the harm has not yet occurred?

No explicit condition has been found from scholars stating that the blessing (tabreek) must occur upon admiration. However, the phrase "idh" (when/since) in the noble Qur'anic verse and the noble Prophetic Hadeeth can be understood to imply that tabreek and saying "Ma sha' Allah" are uttered upon admiring something.

It is more appropriate to supplicate for blessing, based on the Hadeeth: "If one of you sees something that he admires in himself, or his wealth, or his brother, let him supplicate for blessing for it, for the evil eye is real." As for the Hadeeth: "Whoever sees something that he admires and says: 'Ma sha' Allah, la quwwata illa billah (What Allah wills, there is no power except with Allah),' the evil eye will not afflict him," it is very weak.

Some scholars are of the opinion that saying "Ma sha' Allah" is legislated; and among what repels the affliction of the evil eye is saying "Ma sha' Allah, la quwwata illa billah."

Ibn Katheer said: "Whoever is pleased with something concerning himself, his wealth, or his child, let him say: 'Ma sha' Allah, la quwwata illa billah.'"

Ibn 'Uthaymeen said: "If a person sees something that he admires, and fears the envy of the evil eye, he should say: 'Ma sha' Allah tabarakallah (What Allah wills, blessed be Allah),' so that the one being observed is not afflicted by the evil eye."