Corpus of Electronic Texts Edition
The Gaelic Maundeville (Author: John Maundeville)

paragraph 127

This Mahomet reigned in Arabia: and at that time the Year of the Lord was 620. And of the race of Ismael, son of Abraham and Hagar, was he, and (some) Saracens are called Ismaelites from Ismael, and others of them Hagarenes from Hagar, and others Ammonites from the two sons that his own daughters bore to Lot, and the true Saracens from Sara herself.