Early royal inscriptions from the third millennium BCE mention "the reeds of Enki". Reeds were an important local building material, used for baskets and containers, and collected outside the city walls, where the dead or sick were often carried. This links Enki to the "Kur" or underworld of Sumerian mythology. In another even older tradition, Nammu, the goddess of the primeval creative matter and the mother-goddess portrayed as having ""given birth to the great gods,"" was the mother of Enki, and as the watery creative force, was said to preexist Ea-Enki. Benito states "With Enki it is an interesting change of gender symbolism, the fertilising agent is also water, Sumerian ""a"" or ""Ab"" which also means "semen". In one evocative passage in a Sumerian hymn, Enki stands at the empty riverbeds and fills them with his 'water'".