The scholars differed concerning the ruling on one who does wudoo’ and wipes over his socks, then takes them off.
Some scholars say that it is sufficient for him to wash his feet, and his wudoo’ is completed thereby.
This is a weak view, because wudoo’ requires continuity, i.e., there should not be a long time between the washing of the various parts, rather they should be washed one after another, in a continuous sequence.
Hence Ibn Qudaamah (may Allaah have mercy on him) narrated in al-Mughni (1/367) that this view is based on the idea that there is no need for continuity in wudoo’, and this is weak.
Others said that the person’s wudoo’ is invalidated thereby, and if he wants to pray he has to repeat his wudoo’. They quoted as evidence the fact that wiping takes the place of washing, and if the socks are removed the purity of the feet is no longer valid, because now they are unwashed and unwiped. If the purity of the feet is invalidated then the entire wudoo’ is invalidated because it cannot be divided up. This view was favoured by Ibn Baaz (may Allaah have mercy on him), as is stated in his Majmoo’ al-Fataawa, 10/113.
Yet others said that his wudoo’ is not invalidated thereby unless he breaks his wudoo’ in some other way (by breaking wind etc). This was the view of a number of the salaf, including Qataadah, al-Hasan al-Basri and Ibn Abi Layla. It was supported by Ibn Hazm in al-Muhalla (1/105), and was the view favoured by Shaykh al-Islam Ibn Taymiyah and Ibn al-Mundhir. Al-Nawawi said in al-Majmoo’ (1/557): this is the strongest view.
They quoted a number of things as evidence for that:
1 – That purity is not invalidated except by hadath (breaking one's wudoo’ by breaking wind etc.) and taking off the socks is not hadath.
2 – The purity of one who wipes over his socks is established by shar’i evidence, and it cannot be ruled to be invalid except by further shar’i evidence, and there is no evidence to indicate that purity is invalidated by taking off the socks.
3 – The analogy with shaving the hair after doing wudoo’. If a person does wudoo’ and wipes over his hair, then shaves his head, he remains in a state of purity and it is not invalidated by that. The same applies to one who wipes over his socks then takes them off.
Shaykh Ibn ‘Uthaymeen said:
If a person takes off his socks after wiping over them, his wudoo’ is not invalidated thereby, and he may pray as he likes until he breaks his wudoo’ (hadath), according to the correct view.
End quote, from Majmoo’ Fataawa Ibn ‘Uthaymeen, 11/193.
See also: al-Mughni, 1/366-386; al-Muhalla, 1/105; al-Ikhtiyaaraat, p. 15; al-Sharh al-Mumti’, 1/180.