One most important time for Ista-aaza is the moment of commencement of a prayer. Whenever a person has to offer prayer to Allah, he should seek protection from Him against Iblees who is always bent on misguiding and taking him astray from the right path. Iblees makes his utmost efforts to destroy the good deeds of the human being that he is deprived of the rewards that he might earn. Atleast Iblees, or Satan, tries to make the person proud or deceitful about prayers.

For example, if one wishes to do the ablutions, he must do the Ista-aaza before commencing to do it by asking for Allah's Protection against the accursed Satan. The ablution should be done only after doing Ista-aaza. You must have noticed that many a time the same ablution becomes the Satan's area of operation that he puts many lurking fears or temptations in the mind of the person that make his entire prayer null and void.

Therefore, Ista-aaza is one of the most important aspects of prayer that has to be performed in the truest sense, and implicitly, that Allah's protection from the accursed Satan is assured.