I hold the view that it is obligatory to rinse the mouth and nose when performing ablutions (wudū’). This is a view found in the Hanbalī school of law.
The other three schools of law – the Hanafī, Mālikī, and Shāfi`ī schools, hold the view that rinsing the mouth and nose are Sunnah acts. Their main argument is that this verse which describes how to perform wudū' makes no mention of rinsing the mouth or inhaling water into the nostrils. They further argue that when the Prophet (peace be upon him) was asked about how to perform wudū', he referred to this verse.
However, the opinion that these two acts are obligatory aspects of wudū’ has the most compelling evidence for it from the Sunnah.
Prophet (peace be upon him) said: “When one of you performs wudū', he should take water into his nose and then exhale it…” [Sahīh al-Bukhārī
and Sahīh Muslim
This hadith is persuasive evidence that inhaling water into the nostrils is obligatory during wudū', since the Prophet (peace be upon him) ordered us to do it.
This line of evidence also indicates that exhaling the water is equally obligatory. Ibn Qudāmah's discussion in the Hanbalī law book al-Mughnī
indicates that this is indeed the case; that the obligation of inhaling water into the nostrils during wudū' is not fulfilled unless that water is exhaled as well.
Likewise, the Mālikī scholar Ibn `Abd al-Barr, writes in al-Tamhīd (4/33):
As for exhaling and inhaling water into the nostrils, they are basically the same in meaning. Inhalation requires taking water into the nasal cavity while exhalation requires expelling it out of the nasal cavity after taking it in. This is the literal meaning of the two words… However, most scholars suffice by mentioning only one of these two words, though both are related to us from the Prophet (peace be upon him).
The Prophet (peace be upon him) also said: “Perform wudū' well, run your fingers between each other, and exaggerate in inhaling water unless you are fasting.” [Sunan Abī Dāwūd
, Sunan al-Nasā'ī
, Sunan al-Tirmidhī
, Sunan Ibn Mājah
, and Sunan al-Bayhaqī
] It is an authentic hadīth.
The fact that the Prophet (peace be upon him) commanded us to exaggerate in inhaling water into our nostrils when we are not fasting indicates that even when we are fasting, we should inhale water without exaggeration. Therefore, this gives a strong indication of the obligatory nature of the act.
In the narration of this hadith found in Sunan Abī Dāwūd
and Sunan al-Bayhaqī
, it is mentioned that the Prophet (peace be upon him) said: “When you perform wudū', rinse your mouth.” The chain of transmission for the narration of this hadith containing this addition has been authenticated by Ibn Hajar al-`Asqalānī and al-Nawawī. Ibn Muflih and al-Dhahabī have both said: “Its chain of transmission is good.”
Moreover, the Prophet (peace be upon him) had always made sure to rinse his mouth and inhale water into his nostrils when he performed wudū'. This is what is conveyed to us by all the Companions who took care to observe his wudū', like `Uthmān, `Alī, `Abd Allah b. `Amr b. al-`As, Abū Hurayrah, `A'ishah, al-Rabī`, `Abd Allah b. Zayd b. `Asim, al-Miqdām b. Ma`d Yakrib, Ibn `Abbās, Wā'il b. Hajar, and Mu`āwiyah.
In fact, more than twenty-two Companions have described the Prophet's wudū', and not one of them has ever failed to mention that he rinse his mouth and inhale water into his nostrils. Ibn Qudāmah points out in al-Mughnī
that this is the case even when the Prophet (peace be upon him) shortened his wudū' to its bare essentials, performing each act only once instead of thrice. This point has also been mentioned by Ibn Taymiyah, Ibn al-Qayyim, and al-Shawkānī.
Ibn `Abd al-Barr writes in al-Istidhkār
Not one single person has preserved for us from the Prophet (peace be upon him) that he ever left out rinsing his mouth or inhaling water into his nostrils from either his wudū' or from his ghusl, and he is the one who makes clear Allah's intended meaning.
Admittedly, the mere practice of Allah's Messenger (peace be upon him), however much he may repeat it, is not an indication of it being obligatory, unless there is other evidence to support its being so. This is a well-known principle of jurisprudence. However, Ibn Qudāmah points out:
It is because this action of his is suitable for being an explanation depicting in detail the wudū' that is prescribed in Allah's Book, since they (i.e. the mouth and nose) are two features of the face that are not difficult to wash.
The argument here is that Allah says: “O you who believe! When you rise to perform your prayers, wash your faces…” [Sūrah al-Mā'idah
As for the practice of the Prophet (peace be upon him) when he performed his wudū', it clarifies for us what Allah's intends when He commands us to wash our faces, which is to rinse the mouth and the nose as well as to wash the rest of the face.
And Allah knows best.