Sahih Ibn Khuzaymah

Hazrat Aamir bin Sa’d narrates from his respected father Sayyiduna Sa’d (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) would turn his head to the right side (to such an extent) that the whiteness of his cheek would become visible, and he would also turn his head to the left side until the whiteness of his cheek would become visible.

Sayyiduna Sa’d bin Abi Waqqas (may Allah be pleased with him) narrates that I saw the Prophet (peace and blessings of Allah be upon him) turning for salam to the right and to the left, (he would turn his face so much that) the whiteness of his blessed cheek would become visible. Imam Zuhri (may Allah have mercy on him) says that we have not heard this narration from the hadith of the Messenger (peace and blessings of Allah be upon him), so (the narrator of the hadith) Hazrat Isma’il asked, “Have you heard all the ahadith of the Prophet (peace and blessings of Allah be upon him)?” He replied, “No.” He asked, “Have you heard two-thirds?” He replied, “No.” Hazrat Isma’il asked, “Have you heard half of the ahadith?” He replied, “No.” Hazrat Isma’il said, “This hadith is among those half of the ahadith which you have not heard.”