Al-Suyūṭī attributed this hadith in al-Jāmiʿ al-Kabīr (The Great Compendium) to al-Ṭabarānī in al-Kabīr (The Major Collection) and al-Bayhaqī in al-Shuʿab (The Branches).
The passage referred to is corroborated by a hadith of Abū Hurayrah attributed to the Prophet. It was narrated by al-Bukhārī and others. At its end is the additional wording: “Whoever among you is able to extend the brightness of his blaze, let him do so.” However, this is an interpolation in the hadith and is not authentic, as you will see explained in detail in al-Ḍaʿīfah (The Weak Series), no. 1030.
Unfamiliar terms in the hadith: “enclosure” refers to a pen made for animals from stones and tree branches; its plural is “enclosures.” “Black” is the plural of “black.” “Jet-black” is the plural of “solid-black,” which originally denotes that whose colour is not mixed with any other colour, as stated in al-Nihāyah; that is, the colour of these horses is pure black, unmixed with any other colour. “White-legged” describes a horse whose white markings rise on its legs to the place of the fetters, extending beyond the fetlocks but not past the knees, since that is where anklets and fetters are worn. Such markings are not found on one or both forelegs alone unless they are accompanied by markings on one or both hind legs.
Note: In the Musnad, the word “enclosure” appears as “heap,” which is a typographical error. I had likewise transmitted it in this form along with the hadith in my book The Description of the Prayer / The Merit of Prostration, and in the footnote I gave it the vowel u and explained it as “a heap.” By Allah, this was the height of heedlessness, for this meaning plainly bears no relation to the context of the hadith. But that is hardly surprising, since it only confirms that I truly am an Albanian! This error persisted through every edition of the book until