On the authority of his father, he said: I said, "O Messenger of Allah, tell me about the ablution (wuḍūʾ)." He said: "Perform the ablution thoroughly, and exaggerate in snuffing water up the nose (al-istinshāq), unless you are fasting."(1)

72 - Chapter: The command to blow the nose (al-istinthār)

88 - Qutaybah informed us, from Mālik. Likewise: Isḥāq ibn Manṣūr informed us, saying: ʿAbd al-Raḥmān narrated to us, from Mālik, from Ibn Shihāb, from Abū Idrīs al-Khawlānī,
from Abū Hurayrah, that the Messenger of Allah, peace and blessings be upon him, said: "Whoever performs ablution, let him blow his nose, and whoever uses stones for cleansing (istijmār), let him do so an odd number of times."(2)

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(1) Its chain from the route of Sufyān (i.e., al-Thawrī), from Abū Hāshim (i.e., Ismāʿīl ibn Kathīr), is ṣaḥīḥ. As for its chain from the route of Yaḥyā ibn Sulaym (i.e., al-Ṭāʾifī), from Ismāʿīl ibn Kathīr, it is ḥasan on account of Yaḥyā. Wakīʿ: he is Ibn al-Jarrāḥ al-Ruʾāsī. The ḥadīth is in al-Sunan al-Kubrā from Isḥāq ibn Ibrāhīm, no. (99).
It was also recorded by Abū Dāwūd (142) from Qutaybah ibn Saʿīd, with the first chain, in extended form with the story of Laqīṭ ibn Ṣabrah's arrival before the Messenger of Allah, peace and blessings be upon him, in the delegation of Banū al-Muntafiq, and it includes the addition: "And interlace between the fingers."
It was recorded in extended and abridged forms by al-Tirmidhī (788), Ibn Mājah (407) and (448), and Ibn Ḥibbān (1054), (1087), and (4510) via multiple routes, from Yaḥyā ibn Sulaym, and with some of them there is the addition: "And interlace between the fingers."
It was recorded by Aḥmad (16380) and (16381), al-Tirmidhī (38) via the route of Wakīʿ; Aḥmad (16383), and the author in al-Sunan al-Kubrā (3035) via the route of ʿAbd al-Raḥmān ibn Mahdī; and the author also (116) via the route of Yaḥyā ibn Ādam — all three of them (Wakīʿ, ʿAbd al-Raḥmān, and Yaḥyā) from Sufyān al-Thawrī, with it, and some of the narrations are abridged.
It was recorded by Aḥmad (16384) and (17846) via the route of Ibn Jurayj, from Ismāʿīl ibn Kathīr, with it, in extended form with the story of the delegation of Banū al-Muntafiq, and Ibn Jurayj explicitly stated in both that he heard it directly (al-taḥdīth), thus removing any suspicion of his tadlīs.
The ḥadīth will follow at no. (114).
(2) Both of its chains are ṣaḥīḥ. ʿAbd al-Raḥmān: he is Ibn Mahdī. It is in al-Sunan al-Kubrā, no. (95).
It was recorded by Aḥmad (7221) from ʿAbd al-Raḥmān ibn Mahdī with the second chain, and in it: "let him blow his nose (fal-yanthir)" instead of "let him blow his nose (fal-yastanthir)." =