what images do duncan's words in act 1 scene 4 conjure up?

When Macbeth hears that Malcolm will be the next king, he has horrid pictures in his head of how he would have to "kill" to get to the throne since Malcolm now stands in his way. Duncan expresses regret that the Thane of Cawdor, now executed, was someone in whom "he put trust," a trust that was betrayed. Which specific words?

Theirs no specific words that the question relates to it's just Duncan's words that he says in scene 4 of act 1