Description of the attributes of the Pond of al-Kawthar

It is narrated from Abu Sallam al-Aswad that it reached Umar bin Abd al-Aziz (may Allah have mercy on him) that he narrated the hadith about the Pond (al-Kawthar) via Sayyiduna Thawban (may Allah be pleased with him). So he sent for him, and he was brought on the post horses (al-barid). When he arrived and entered, he greeted with salam and said: "O Commander of the Believers, riding the post mount has been very hard on my legs." Umar bin Abd al-Aziz said with sympathy: "O Abu Sallam, we did not intend to cause you hardship, but a hadith reached me which you narrate via Sayyiduna Thawban (may Allah be pleased with him) from the Prophet (peace and blessings be upon him) about the Pond (al-Kawthar), and I wanted to hear it from your own lips, face to face." Abu Sallam said: I heard Sayyiduna Thawban (may Allah be pleased with him) say that the Messenger of Allah (peace and blessings be upon him) said: "My Pond is as wide as (the distance) from Aden to Amman al-Balqa'. Its water is whiter than milk and sweeter than honey, and its cups are as numerous as the stars. Whoever drinks a single draught from it will never feel thirst afterward. The first to arrive at it will be the poor among the Muhajirun, with dishevelled hair and soiled clothes, those who cannot marry women of comfort and luxury, and for whom (the great people's) doors are not opened." (On hearing this,) Umar bin Abd al-Aziz said: "But I have married a woman of comfort and luxury, Fatimah bint Abd al-Malik, and doors are opened for me. Now I will not wash my head until it becomes dishevelled, nor (will I wash) the garment that touches my body until it becomes dirty."
This hadith is sahih al-isnad (its chain is authentic), but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Samurah bin Jundub (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Hold fast to these white garments. Let your living wear them, and shroud your dead in them, for they are among the best of your garments."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it, because Sufyan bin Uyaynah and Isma'il Ibn Ulayyah narrated it from Ayyub in mursal form.

In the narration of Sufyan bin Uyaynah from Sayyiduna Samurah bin Jundub (may Allah be pleased with him), it is mentioned that the Prophet (peace and blessings be upon him) said: "Hold fast to these white garments. Let your living wear them, and shroud your dead in them."

The wording of the narration of Isma'il Ibn Ulayyah from Sayyiduna Samurah bin Jundub (may Allah be pleased with him) is that the Messenger of Allah (peace and blessings be upon him) said: "Hold fast to these white garments. Let your living wear them, and shroud your dead in them, for they are the best of your clothing."