Washing the Nose & Expelling Water

Abu Hurairah (radhiAllaahu’anhu) narrates that the Prophet (sallallaahu ‘alaihi wa sallam) said

When one of you makes wudoo then let him enter water into his nose, then expel it.

[Al-Bukhaaree (al-Fath, 1/229), Muslim (no.237), Abu Dawood (no. 140)].

Exerting in sniffing in the water as long as you are not fasting is reported in the hadeeth of Laqeet (radhiAllaahu ‘anhu) who said:

O Rasoolullah (sallallaahu ‘alaihi wa sallam), inform me of the wudoo .

He said Complete the wudoo and rub between the fingers and exert in breathing in the water into the nose unless you are fasting.

[Abu Dawood, no.l42; At-Tirmidhee, no.38; An-nasaa’ee, no.ll4; 
Ibn Maajah, no.407; and others]. 

It is clear from these two ahaadith that washing the mouth and nose are both obligatory (waajib). Ibn Qudaamah says in ‘al-Mughnee’: Washing the nose and washing the mouth are both obligatory in both forms of purification – Ghusl and wudoo – as washing the face is obligatory in both of them in the established view of the madhhab; and it is the saying of Ibn al-Mubaarak, Ibn Abi Lailaa and Ishaaq, and it is reported from ‘Ataa.