 The Tayy's progenitor, according to early Arab genealogists, was Julhumah ibn Udad, who was known as "Tayy" or "Tayyi".The theory in some Arab tradition, as cited by 9th-century Muslim historian al-Tabari, holds that Julhumah's "laqab" (surname) of "Ṭayyiʾ" derived from the word "ṭawā", which in Arabic means "to plaster".He received the name because he was said to have been "the first to have plastered the walls of a well", according to al-Tabari.