How does the author use foreshadowing in Wine in the Wilderness?

Early in the play, Bill describes the meaning of his triptych, "Wine in the Wilderness" to Oldtimer. "Once, a long time ago, a poet named Omar told us what a paradise life could be if a man had a loaf of bread, a jug of wine and... a woman singing to him in the wilderness. She is the woman, she is the bread, she is the wine, and she is the singing." This story foreshadows Bill's meeting with Tommy, who he will come to see as the ideal woman.