Therefore...
Therefore, Isti’adha is one of the most important aspects of prayer that has to be performed in the truest sense, and implicitly, that Allah (S.w.T.)’s protection from the accursed Satan is assured. Absolute necessity of Isti’adha in permissible affairs In permissible ( mustahab ), or day-to-day, affairs like eating food, drinking water or wearing the clothes, Isti’adha is mandated.
For example, at the time of wearing the clothes one should recite: Allahummas-stur awrati wa laa taj’al ash-shaitan lahu naseeba (O Allah! Keep my private parts hidden and save them from the interference of shaitan) In every situation, however lowly and futile, or elevated and likeable, one should seek protection from Satan. While entering into the mosque, one should do the Isti’adha lest the persistent Satan chases you even at that threshold!
Even while going to a washroom it is required to do the Isti’adha as follows: Allahumma inni audhu bika minal khabeesil khabs ar-rijs al-khabs ash-shaitanir rajeem (O Allah I seek Your Protection from the accursed Satan and the defiled impurities) Satan at the Threshold of the Mosque One pious person said that he noticed Satan, in apocalyptic revelation, standing at the threshold of the mosque. He asked him “O accursed one!
What are you doing here?” Satan replied, “Some of my associates have been missed in these environs and I am waiting for them!” The pious person understood that they must be intelligent persons who have gone into the mosque and the accursed Satan was unable to follow them inside. They must have taken care to say the Isti’adha before entering the mosque. Reciting the Isti’adha before starting out of one’s House Isti’adha is absolutely essential when one is going out of the residence.
At that time Satan awaits for the person outside. One should do the Isti’adha and recite the following supplication at the moment of emerging out of the house: Bismillahi wa billahi aamantu billahi tawakkaltu ‘alal laahi wa la hawla wa la quwawata illa billaah (In the name of Allah (S.w.T.) and with His Help; I believe in Allah and place my trust in Him.