A classical report says that a woman repeatedly looked in on Sa'd ibn Abi Waqqas, may Allah be pleased with him, despite his warning her to stop. The report says that she later looked in while Sa'd was performing ablution, after which he uttered the phrase “shaha wajhuki.” The same report then states that her face turned toward the back of her head. Ibn Abi al-Dunya preserves the earliest checked form and al-Lalaka'i includes it among Sa'd's karamat, but the principal route passes through Mina, mawla of Abd al-Rahman ibn Awf, whom major hadith critics regarded as abandoned or unreliable.
At that point, the report says that Sa'd uttered the phrase “shaha wajhuki.” The narration then attributes an extraordinary physical outcome to the incident: it says that the woman's face turned toward the back of her head. The report does not give her name, does not describe a medical process, and does not explain the event through any anatomical mechanism. Its public presentation therefore needs to remain within the wording actually preserved in the classical source.
The earliest checked form of the story is preserved by Ibn Abi al-Dunya in Mujabu al-Da'wa. Al-Lalaka'i later transmits the same basic account in his section on the karamat of Sa'd ibn Abi Waqqas. Ibn Kathir and al-Dhahabi also preserve the story in later historical or biographical reception. These later appearances show that the report circulated in Sunni classical literature and was received as an extraordinary account connected with Sa'd.
The transmission evidence, however, places an important limit on how strongly the event can be stated. The principal route runs through Mina, the mawla of Abd al-Rahman ibn Awf. Al-Dhahabi explicitly calls Mina “matruk,” and the Task 1 narrator review records that multiple hadith critics rejected or severely weakened him. Al-Lalaka'i and the later historians substantially depend on the same route family rather than supplying a separate strong chain.
For that reason, the report should not be turned into an authenticated historical certainty. The most careful conclusion is that classical Sunni sources do preserve a story in which a woman ignored Sa'd's warning, looked in while he was making ablution, heard an attributed utterance from him, and was then said to have suffered a dramatic change in the position of her face. The story has clear classical karamah reception, but the exact extraordinary outcome rests on a very weak transmission route. It is therefore best presented as a low-confidence reported karamah requiring editorial review.
Conclusion
Classical Sunni sources preserve a report that a woman who repeatedly ignored Sa'd ibn Abi Waqqas's warning later suffered an extraordinary change after looking in on him during ablution. Because the principal route runs through a narrator judged abandoned, the story should remain a low-confidence reported karamah rather than an authenticated historical certainty.