Is it legislated to say aloud the الاستعاذة "أعوذ بالله من الشيطان الرجيم" (I seek refuge in Allah from Satan, the accursed) in the first two rak'ahs of a prayer recited aloud?

It is better to say the isti‘adhah (seeking refuge with Allah) silently when beginning the recitation in prayer. Ibn Qudamah mentioned that he knows of no disagreement regarding the desirability of saying it silently. Al-Nawawi, in Al-Majmu‘, reported that the more correct opinion is the desirability of saying the isti‘adhah silently, contrary to those who said it is desirable to say it aloud because it follows the recitation, or that one has a choice between the two. Therefore, the preponderant opinion is the desirability of saying the isti‘adhah silently before recitation in prayer, and the prayer is valid if it is said aloud.