On the authority of some of the Companions of the Prophet ﷺ: that the Prophet ﷺ saw a man praying, and on the top of his foot there was a spot the size of a dirham that water had not reached, so the Prophet ﷺ commanded him to repeat the ablution and the prayer.¹

66 - Chapter: On Doubt Regarding the Breaking of Ablution

176 - Qutaybah ibn Saʿīd and Muḥammad ibn Aḥmad ibn Abī Khalaf narrated to us, they said: Sufyān narrated to us, from al-Zuhrī, from Saʿīd ibn al-Musayyab and ʿAbbād ibn Tamīm, from his paternal uncle: A man complained to the Prophet ﷺ about experiencing something during prayer until it seemed to him [that he had broken his ablution], so he said: "He should not leave [the prayer] until he hears a sound or perceives an odor."²

--------------------------------------------
¹ Ṣaḥīḥ li-ghayrihi (authentic through corroborating evidence), but this chain is weak. Baqiyyah — that is, Ibn al-Walīd — practices tadlīs al-taswiyah (concealment of weak narrators in the chain), so his explicit statement of hearing from his shaykh is not sufficient according to Aḥmad; rather, he must explicitly state it at every level of the chain. Moreover, he is weak in himself.
Al-Bayhaqī also transmitted it in 1/83 from the author's path, with this chain. In it, Buḥayr ibn Saʿd was corrupted to Yaḥyā ibn Saʿīd.
Aḥmad also transmitted it (15495) via Baqiyyah ibn al-Walīd, with it.

² Its chain is authentic. Sufyān: he is Ibn ʿUyaynah. Al-Zuhrī: he is Muḥammad ibn Muslim. The paternal uncle of ʿAbbād ibn Tamīm: he is ʿAbd Allāh ibn Zayd al-Anṣārī al-Māzinī.
Al-Bukhārī also transmitted it (137) and (177), Muslim (361), al-Nasāʾī in al-Kubrā (151), and Ibn Mājah (513) via Sufyān ibn ʿUyaynah, with this chain. Al-Bukhārī's narration in the second location is from ʿAbbād ibn Tamīm alone.
It is also in Musnad Aḥmad (16450) and Sharḥ Mushkil al-Āthār (5100).
There is disagreement regarding the narration of Saʿīd ibn al-Musayyab: whether it is directly from the Prophet ﷺ, making it mursal (interrupted at the Companion level), or whether it is also from ʿAbd Allāh ibn Zayd. Al-Mizzī in al-Tuḥfah held the second view, while al-Dāraquṭnī in al-ʿIlal 4/397 held the first, supported by the fact that ʿAbd al-Razzāq transmitted it in his Muṣannaf (534) via al-Zuhrī, from Saʿīd ibn al-Musayyab as mursal. The mursal narrations of Saʿīd are strong, and it has also been authentically transmitted as connected (mawṣūl) via the path of ʿAbbād ibn Tamīm.