I saw the Prophet ﷺ wipe over the leather socks on their upper surface.
رأيت النبي يمسح على الخفين على ظاهرهما.
Abu Dawud (161) narrated it from Muhammad bin Sabbah Bazzar, and Tirmidhi (98) also narrated it from Ali bin Hajar, both of them from Abdul-Rahman bin Abu Zinad, from his father, from Urwa bin Zubayr, from Mughira bin Shuba, and he related the hadith. The wording given is that of Tirmidhi, while the wording of Abu Dawud is, "He used to wipe over the leather socks." Abu Dawud said, "Someone other than Muhammad (meaning Ibn Sabbah Bazzar) said, 'over the top of the leather socks.'" This indicates that the one who said "over the top of the leather socks" was Ali bin Hajar.However, there is disagreement regarding Abdul-Rahman bin Abu Zinad. Muhammad bin Sabbah and Ali bin Hajar both narrated from him, as you see, from his father, from Urwa bin Zubayr. But Abu Dawud Tayalisi (number 727, as edited by Dr. Turki) narrated it, and Bayhaqi (1/291) narrated from him, from Ibn Abu Zinad, from his father, from Urwa bin Mughira, from Mughira bin Shuba, that the Prophet ﷺ wiped the outer surface of his leather socks. Bayhaqi then said, "This is how Abu Dawud Tayalisi narrated it from Abdul-Rahman bin Abu Zinad. Ismail bin Musa likewise narrated it from Ibn Abu Zinad. But Sulayman bin Dawud Hashimi, Muhammad bin Sabbah, and Ali bin Hajar narrated it from Ibn Abu Zinad, from his father, from Urwa bin Zubayr, from Mughira." End of quote.It appears that Abdul-Rahman bin Abu Zinad erred in identifying which Urwa was meant, though this error causes no harm, since he only wavered between two trustworthy narrators, Urwa bin Zubayr and Urwa bin Mughira. As for Abdul-Rahman bin Abu Zinad himself, opinions differ regarding his reliability. The conclusion is that he was truthful (saduq). Ajli deemed him reliable, and Ibn Adi said he was among those whose hadith is recorded. Ibn Main, however, said, "He is of no significance," and Nasai said, "His hadith is not to be relied upon as proof."I say, a narrator of this caliber can be cited as corroborating support, and this is why Tirmidhi graded his hadith hasan.As for what has been reported from Mughira bin Shuba, that the Messenger of Allah ﷺ wiped the top and bottom of the leather sock, this is defective (mu'allal). It was narrated by Ibn Majah (550), Abu Dawud (165), and Tirmidhi (97), all of them through Walid bin Muslim, who said, "Thawr bin Yazid told us, from Raja bin Haywa, from Warrad, the scribe of Mughira, from Mughira," and he related it. The wording given is that of Ibn Majah.Abu Dawud said, "It has reached me that Thawr did not hear this hadith from Raja." Tirmidhi said, "This is a defective hadith. No one but Walid bin Muslim connected it with a full chain going back through Thawr bin Yazid. I asked Abu Zura and Muhammad bin Ismail about this hadith, and they both said, 'It is not sahih, because Ibn Mubarak narrated this from Thawr, from Raja bin Haywa, who said, "I was told, on the authority of Mughira's scribe, from the Prophet ﷺ," as a mursal report, without mentioning Mughira in it.'" This is what he said in the Sunan. And in the Ilal (1/180) he said, "I asked Muhammad about this hadith, and he said, 'This is not sound. It has been narrated from Ibn Mubarak, from Thawr bin Yazid, who said, "I was told, on the authority of Raja bin Haywa, from Mughira's scribe, from the Prophet ﷺ," as a mursal report,' and he judged it weak. I also asked Abu Zura, and he said something similar to what Muhammad bin Ismail had said."