In Act 1, scene 3, Macbeth and Banquo initially encounter the Weird Sisters. They speak, at first, to Macbeth alone.
FIRST WITCH: All hail, Macbeth! Hail to thee, Thane of Glamis!
SECOND WITCH: All hail, Macbeth! Hail to thee, Thane of Cawdor!
THIRD WITCH: All hail, Macbeth! Hail to thee, that shalt be king hereafter! (1.3.51-53)
The first statement is not prophetic because Macbeth already is the Thane of Glamis. The second statement is technically not a prophecy either because Duncan has already named Macbeth the Thane of Cawdor; Macbeth just doesn't know it yet. The final statement, if one believes that fate controls one's destiny in this play, is prophetic because Macbeth has not yet been named king of Scotland (1.3.53).
Banquo asks for some news of his own future, and the next prophecy pertains to him.
FIRST WITCH: Lesser than Macbeth and greater.
SECOND WITCH: Not so happy, yet much happier.
THIRD WITCH: Thou shalt get kings, though thou be none. (1.3.68-70)
In this prophecy, the Weird Sisters tell Banquo that he will not be king himself, but that he will father a line of kings. All three of these lines are prophetic because they all speak to Banquo's future and things that have not yet taken place.