The version recorded in Syriac is of particular importance because it was current in the Middle East during the time of the Quran's writing and is regarded as being closely related to the literary and linguistic origins of the story of Dhul-Qarnayn in the Quran. The Syriac legend, as it has survived, consists of five distinct manuscripts, including a Syriac Christian religious legend concerning Alexander and a sermon about Alexander ascribed to the Syriac poet-theologian Jacob of Serugh (451–521 AD, also called Mar Jacob), which according to Reinink was composed around 629–636. The Syriac Christian legend concentrates on Alexander's journey to the end of the World, where he constructs the "Gates of Alexander" to enclose the evil nations of "Gog and Magog", while the sermon describes his journey to the "Land of Darkness" to discover the "Water of Life" (Fountain of Youth). These legends concerning Alexander are remarkably similar to the story of Dhul-Qarnayn found in the Quran.