The later legend derives from the "Water of Life" tale in the Eastern versions of the Alexander Romance, where Alexander and his servant cross the
Land of Darkness to find the restorative spring. The servant in that story is in turn derived from Middle Eastern legends of
Al-Khidr, a sage who appears also in the
Qur'an.
Arabic and
Aljamiado versions of the Alexander Romance were very popular in Spain during and after the period of
Moorish rule, and would have been known to the explorers who journeyed to America.