Does prayer become invalid if the worshiper seeks refuge audibly while in any posture (prostrating or bowing)?

The prayer is not invalidated if the worshipper seeks refuge while bowing or prostrating, whether intentionally or unintentionally. This is because seeking refuge (isti'adha) is a prescribed remembrance (dhikr) in prayer, and performing a prescribed remembrance in a place other than its designated spot does not invalidate the prayer. Seeking refuge is prescribed when reciting the Qur'an, as stated in the verse: "So when you recite the Qur'an, seek refuge with Allah from Satan, the expelled" (16:98). There is a difference of opinion on whether it is prescribed in every unit (rak'ah) or only in the first one, with Ibn al-Qayyim favoring the view that it is only in the first unit. It is also prescribed if Satan confuses the worshipper during prayer, by seeking refuge with Allah and spitting lightly to the left three times.