The Druids are represented as being able to foretell the future and to perform magic. Before setting out on the great expedition against Ulster, Medb, queen of Connaught, goes to consult her Druid, and just before the famous heroine Derdriu (Deirdre) is born, Cathbu prophesies what sort of a woman she will be.
Hence the prophet prophesies of a definite future arising out of and organically connected with the present.
The muse reassures her, and prophesies the downfall of the tyrant.
Edify for others, that's why he says "He that prophesies edifies the church."
A Chaldaean sage prophesies to him his future greatness, and another Persian slave, Oebares, becomes his associate.