The Messenger of Allah ﷺ sent out a military expedition, and they were struck by intense cold. When they returned to the Messenger of Allah ﷺ, he instructed them to wipe over their head coverings and footwear.
بعث رسول الله ﷺ سرية فأصابهم البرد، فلما قدموا على رسول الله ﷺ أمرهم أن يمسحوا على العصائب والتساخين.
Abu Dawud narrated it (146) from Ahmad bin Muhammad bin Hanbal, who said, Yahya bin Saeed narrated to us, from Thawr, from Rashid bin Saad, from Thawban, and he mentioned it. It is also in Musnad Imam Ahmad (22383). Its chain is hasan, as was mentioned earlier regarding wiping over leather socks and the turban. As for "tasakhin", it refers to anything used to warm the foot, such as leather socks, woolen socks, and the like.Tirmidhi said, this is the view of more than one scholar, and it is held by Sufyan Thawri, Ibn Mubarak, Shafii, Ahmad, and Ishaq. They said that one may wipe over woolen socks even if they are not worn with sandals, provided they are thick.He said, and on this topic there is also a report from Abu Musa.He also said, I heard Salih bin Muhammad Tirmidhi say, I heard Abu Muqatil Samarqandi say, I visited Abu Hanifa during the illness from which he died. He asked for water, performed wudu while wearing woolen socks, and wiped over them. Then he said, "Today I have done something I never used to do. I wiped over woolen socks that were not worn with sandals." End of quote.Shaykh al-Islam said in his fatwas, "It is permissible to wipe over woolen socks, if one walks in them, whether or not they are reinforced with leather, according to the most correct of the two scholarly positions. For in the Sunan it is reported that the Prophet ﷺ wiped over his woolen socks and his sandals. Even if this hadith is not established, analogy still requires this ruling. The only difference between woolen socks and sandals is that one is made of wool and the other of leather, and it is well known that such a difference has no bearing in Islamic law. So there is no distinction between something being made of leather, cotton, linen, or wool, just as no distinction is made between wearing black or white clothing during ihram. At most, leather lasts longer than wool, but this has no legal effect, just as the strength of leather has no effect. Rather, wiping is permissible whether the material is durable or not. Moreover, it is well known that the need to wipe over one is exactly like the need to wipe over the other. Given this equivalence in underlying wisdom and need, distinguishing between them would mean separating two things that are essentially alike. This goes against justice and sound reasoning as established by the Book and the Sunnah, and by what Allah revealed in His books and sent through His messengers. Whoever distinguishes between them on the grounds that water passes through one but not the other has cited a superficial distinction with no real effect. And if someone were to say that water reaches the wool more than the leather, making wiping over it even more fitting since the purifying water clings to it more, this description would be more worthy of consideration than the other, and closer to the effective qualities. Yet even that remains closer to a superficial description, and both are invalid." End of quote.On this topic there is also the hadith of Abu Musa, which Abu Dawud and Tirmidhi referred to. Ibn Majah narrated it (560), that the Prophet performed wudu and wiped over his woolen socks and sandals.He narrated it from Muhammad bin Yahya, who said, Mualla bin Mansur and Bishr bin Adam narrated to us, they said, Isa bin Yunus narrated to us, from Isa bin Sinan, from Dahhak bin Abdul-Rahman bin Arzab, from Abu Musa Ashari, and he mentioned the hadith.It has two defects, as Abu Dawud pointed out. The first is that the chain is not connected, since Dahhak bin Abdul-Rahman never met Abu Musa Ashari. The second is that it is not strong, since Isa bin Sinan, the narrator from Dahhak, is daif. He was declared daif by Ahmad, Ibn Main, Abu Zura, Nasai, and others.