Yehuda Halevi, who wrote both secular and devotional poems, is considered one of the finest poets in post-biblical Hebrew literature. Suffused with warmth, moving easily between the mundane and the otherworldly, and, above all, delicately elegiac, the poet's voice cuts across all the literary genres and religious modes on which he drew.   Born in the second half of the 11th century, Halevi wandered in his youth between Muslim and Christian Spain before settling in Córdoba around 1110. Towards the end of his life, to the amazement and consternation of his friends and admirers, he set out on a pilgrimage to the Holy Land, at the time under Crusader rule. He arrived in Alexandria in 1140 and recorded his perilous sea voyage in a celebrated sequence of poems, remarkable for their fusion of startling realism and religious longing. Months later Halevi embarked for Palestine. The exact date, location and circumstances of his death have remained a mystery.   Gabriel Levin was born in France in 1948 and grew up in the United States and Israel. His first collection of poems, Sleepers of Beulah, was published in 1992 and his mucb-praised second collection, Ostraca, appeared in late 1999. He lives in Jerusalem.