Take omen of the raven of separation.—The crow and raven were looked upon as birds of ill omen, because in the ceaseless migrations of the Arabs they alighted on each deserted encampment to scratch and search for what they could find, and were consequently taken as emblems of departure and desolation.  This image recurs continually in the poets.  Various kinds of crow were distinguished, one said to be properly the "crow of separation," being of mixed black and white, or with a white breast, or, as others say, a crow with red beak and feet, while the black crow was called ḥâtim, because it decided or announced separation to be inevitable. (The Assemblies of al-Hariri, Hariri-Chenery, v.9, 1867)

... It is told of Hátim of the tribe of Tayy,¹ that when he died, they buried him on the top of a mountain and set over his grave two troughs hewn out of two rocks and stone girls with dishevelled hair...
    ¹ A noble tribe of Badawin that migrated from Al-Yaman and settled in Al-Najd.  Their Chief, who died a few years before Mohammed's birth, was Al-Hátim (the "black crow"), a model of Arab manliness and munificence; and although born in the Ignorance he will enter Heaven with the Moslems.  Hátim was buried on the hill called Owarid:  I have already noted this favourite practice of the wilder Arabs and the affecting idea that the Dead may still look upon his kith and kin.  There is not an Arab book nor, indeed, a book upon Arabia which does not contain the name of Hátim; he is mentioned as unpleasantly often as Aristides. (Thousand Nights and a Night, Smithers, 1894)