Ruling on seeking refuge with Allah (isti‘adhah) before doing wudu
Question

What is the ruling on seeking refuge with Allah (isti‘adhah) before doing wudu?
Praise be to Allah.Some of the scholars stated that seeking refuge with Allah – by saying “A‘udhu Billahi min ash-shaytan ir-rajim (I seek refuge with Allah from the accursed Shaytan) – before doing wudu is recommended (mustahabb).
See: al-Lubab fi Sharh al-Kitab (1/9); Asna’al-Matalib fi Sharh Rawd at-Talib (1/37).
But the hadiths which describe the wudu of the Prophet (blessings and peace of Allah be upon him) – of which there are many – make no mention of seeking refuge with Allah when starting to do wudu, and the scholars who stated that it is recommended did not quote any hadith to prove that. This indicates that the Prophet (blessings and peace of Allah be upon him) did not do that, and the best of guidance is the guidance of the Prophet (blessings and peace of Allah be upon him).
Perhaps it is for this reason that an-Nawawi (may Allah have mercy on him) did not mention it in his book al-Adhkar, and he also did not mention it among the sunnahs and recommended actions of wudu in his two important books, al-Majmu‘ Sharh al-Muhadhdhab and Rawdat at-Talibin.
The scholars of the Permanent Committee for Ifta’ were asked: What is the ruling on doing wudu without reciting the testimony of faith or seeking refuge with Allah?
They replied:
Whoever omits to recite the testimony of faith after finishing wudu has omitted a sunnah action, but his wudu is not rendered invalid by that; rather his wudu remains valid.
As for seeking refuge with Allah, it is not a sunnah in the case of wudu; rather it is prescribed to say Bismillah when starting it.
And Allah is the source of strength. May Allah send blessings upon our Prophet Muhammad and his family and companions.
Permanent Committee for Academic Research and Ifta’.
Shaykh ‘Abdullah ibn Qa‘ud, Shaykh ‘Abd ar-Razzaaq ‘Afifi, Shaykh ‘Abd al-‘Aziz ibn ‘Abdillah ibn Baz."(Fatawa al-Lajnah ad-Da’imah  24/212).
They also said (4/75, Vol.2):
There are no adhkar to be recited when starting wudu or whilst doing it, except what was narrated from the Prophet (blessings and peace of Allah be upon him). That includes saying “Bismillah” when starting to do wudu and saying, after finishing it: “Ashhadu an la ilaha illa Allah wahdahu la sharika lah, wa ashhadu anna Muhammadan ‘abduhu wa rasooluhu. Allahumma ij‘alni min at-tawwabina waj‘alni min al-mutatahhirina (I bear witness that there is no god worthy of worship except Allah alone, with no partner or associate, and I bear witness that Muhammad is His slave and His Messenger. O Allah, make me one of those who repent and make me one of those who purify themselves).”
And Allah is the source of strength. May Allah send blessings upon our Prophet Muhammad and his family and companions.
Permanent Committee for Academic Research and Ifta’.
Shaykh Bakr Abu Zayd, Shaykh Salih al-Fawzan, Shaykh ‘Abdullah ibn Ghadyan, Shaykh ‘Abd al-Aziz Al ash-Shaykh, Shaykh ‘Abd al-‘Aziz ibn ‘Abdillah ibn Baz. End quote.
And Allah knows best.