First, after Duncan learns that Macbeth has defeated the forces of a traitor, the Thane of Cawdor, the king decides to have Cawdor executed and to give Macbeth his title (Act 1, Scene 2):
No more that Thane of Cawdor shall deceive
Our bosom interest. Go pronounce his present death,)
And with his former title greet Macbeth.
I'll see it done.
What he hath lost, noble Macbeth hath won.
Then, after victory is declared, the King speaks to, among others, his son Malcolm, Banquo and Macbeth. He is overjoyed by the turn of events and invites himself to dinner at Macbeth's castle at Inverness (Act 1, Scene 5):
My plenteous joys,
Wanton in fullness, seek to hide themselves
In drops of sorrow. Sons, kinsmen, thanes,
And you whose places are the nearest, know
We will establish our estate upon
Our eldest, Malcolm, whom we name hereafter
The Prince of Cumberland; which honor must
Not unaccompanied invest him only,
But signs of nobleness, like stars, shall shine
On all deservers. From hence to Inverness,
And bind us further to you.
A fatal mistake for old King Duncan.
In a fateful error, King Duncan in the second scene of Act I Shakespeare's play "Macbeth," decides to reward Macbeth for his fearlessness in defeating Macdonwald in battle, not to mention the Norweigan army and the Thane of Cawdor. Duncan, the King of Scotland, orders the death of the traitorous Thane of Cawdor, awarding this position to the "noble Macbeth" as he calls him.
Of course, as the play progresses, the reader cannot help noticing the situational irony of King Duncan's praises for Macbeth, the Scotsman who later proves himself far, far more traitorous than the former Thane of Cawdor. While the supernatural element of the three witches presents itself in the first scene, the influence of the preternatural world and the three sisters upon Macbeth has not yet come about in this second scene. With the contrast between Macbeth in the exposition and Macbeth in the final act, the transformation of Macbeth from fearless and valiant warrior to unconscionable assassin who, in his tragic alignment with the preternatural world is clearly evident where, indeed, "Fair is foul and foul is fair(I,i,11)