my father’s slaves?’ Realising that Ḥamzah was drunk, the Messenger of Allah ﷺ stepped back on his heels and withdrew, and we left with him.

This is al-Bukhārī’s wording.

The ḥadith plainly indicates that the navel is not part of the ʿawrah (the area that must be covered), for the Prophet ﷺ uncovered it and others looked at it. Ibn Ḥazm said, ‘Had the navel been ʿawrah, Allah would not have allowed Ḥamzah—or anyone else—to gaze at it.’

Those who hold that the navel is not ʿawrah include Abū Ḥanīfah and al-Shāfiʿī, and this is the well-known view among the latter’s followers. Some have even claimed consensus on the point, though that claim is debatable.

Other reports address the same question. Among them is the narration of ʿUmayr ibn Isḥāq, who said: ‘I was with al-Ḥusayn ibn ʿAlī when Abū Hurayrah met him and said, “Come closer so that I may kiss from you the spot where I saw the Messenger of Allah ﷺ kiss you.” Al-Ḥusayn lifted his garment, and Abū Hurayrah kissed his navel.’

Al-Ṭaḥāwī recorded this in al-Mushkil through the chain of ʿUthmān ibn ʿUmar; al-Bayhaqī narrated it from Yaḥyā ibn Yaḥyā—Azhur al-Sammān informed us; Aḥmad transmitted it from Ismāʿīl; Muḥammad ibn Abī ʿAdī also transmitted it; and Ibn Abī Shaybah included it in his Musnad, from whom Ibn Ḥibbān placed it in his Ṣaḥīḥ, as cited in Naṣb al-Rāyah. All four report it from Ibn ʿAwf, and the wording belongs to the first of them.