It is narrated from Dhirr that I went to Safwan bin Assal al-Muradi (because) I wanted to ask him about wiping over leather socks. He said: What has brought you to me? I said: The pursuit of knowledge. He said: Shall I not give you glad tidings? I said: Please do. So he narrated, attributing it to the Prophet (peace be upon him), that the Messenger of Allah (peace be upon him) said: "Indeed, the angels spread their wings for the seeker of knowledge, being pleased with what he seeks."
(Commentary on Hadiths 361 to 368) From all these narrations, the encouragement to acquire knowledge and the virtue of a religious scholar are established.
Zirr bin Hubaish narrates: I presented myself before Sayyiduna Safwan bin Assal Muradi (may Allah be pleased with him). He asked me: Why have you come? I replied: For the acquisition of knowledge. He said: The angels spread their wings for the seeker of knowledge, being pleased with his quest. I said: I have some confusion in my mind regarding wiping over the socks after defecation and urination. You are a person who has been in the company of the companions of the Prophet (peace and blessings be upon him), so I have come to ask you whether you have heard the Prophet (peace and blessings be upon him) say anything about this? He replied: The Prophet (peace and blessings be upon him) used to instruct us that when we are traveling (the narrator is in doubt, perhaps these are the words) "when we are travelers, we should not remove our socks for three days and three nights, except in the case of major impurity (janabah). However, after defecation, urination, or sleeping (when wudu is broken), there is no need to remove the socks." I asked: Have you heard the Prophet (peace and blessings be upon him) mention anything about desires of the self? He replied: Yes. Once we were traveling with the Prophet (peace and blessings be upon him), a Bedouin addressed him in a loud voice: O Muhammad (peace and blessings be upon him)! The Prophet (peace and blessings be upon him) replied to him in a voice as loud as his: "Here I am." We said to that Bedouin: Lower your voice, for you have been forbidden from this. He said: No, by Allah! I will not lower my voice. Then he said: O Messenger of Allah! A man loves a people but does not join them. The Prophet (peace and blessings be upon him) said: "A person will be with those whom he loves." The narrator says: Then the Prophet (peace and blessings be upon him) continued to converse with us until he said: "In the direction of the west, there is a door whose width is forty (the narrator is in doubt, perhaps these are the words) or seventy years' journey. Allah Almighty opened it on the day He created the heavens and the earth, and it will not be closed until the sun rises from the west."
Shaykh Muhammad Ibrahim bin Basheer
Benefit: In this hadith, the virtue of the student of knowledge is mentioned, that the angels spread their wings for him. Also, wiping over the leather socks (khuffayn) is established, and a traveler may wipe over the leather socks for three days and three nights. From this hadith, it is also established that every sleep which can be called sleep, whether little or much, nullifies ablution (wudu), because in this hadith, sleep is mentioned alongside urination and defecation. Just as ablution is nullified whether a little or much urine or feces is discharged, likewise, whether sleep is little or much, it also nullifies ablution. Furthermore, in whatever state sleep occurs, ablution is nullified, just as in whatever state urine or feces is discharged, ablution is nullified.
Source: Musnad al-Humaydi: Commentary by Muhammad Ibrahim bin Bashir, Page: 904