Hymns are poems praising the divine and they are used to invoke the God/Goddess in the place in which a ceremony takes place by the Witch of the God/Goddess.
In ancient texts for Hekate we find the first of the orphic hymns the hymn to Hekate (11.835 b.C. or 1366 b.C.). Many years later, Proclus writes an hymn for Hekate and Ianus (400 a.C.). The homeric hymn to Demeter (3000 b.C.)is reffering to Hekate and her power as long as her character. In Greek Magical Papyri (abbreviated PGM) the hymn to Selene is an hymn to Hekate (2nd centrury b.C. to 4rth centrury a.C.). Selene and Hekate were the same Goddess.