Answer:
In Act 2 Scene 3, after the discovery of Duncan's dead body, Malcolm and Donalbain agree to flee from Scotland because they fear for their own lives. However, Macbeth used this against them in the quote: "They were suborned. / Malcolm and Donalbain, the King’s two sons, / Are stol’n away and fled, which puts upon them / Suspicion of the deed." The quote shows that Malcom and Donalbain are now the prime suspects for the murder as they have fled, shortly after the discovery. If they had never left, this wouldn't have happened, and they could have even found themselves inheriting the throne, rather than Macbeth.
Step-by-step explanation:
this is quite rushed, but i hope it helps.
- profparis