Nothing in his life became him like the leaving it
King Duncan:
Is execution done on Cawdor? Are not
Those in commission yet return'd? Malcolm:
My liege,
They are not yet come back. But I have spoke
With one that saw him die; who did report
That very frankly he confessed his treasons,
Implor'd your Highness' pardon, and set forth
A deep repentance. Nothing in his life
Became him like the leaving it.
The traitorous Thane (lord) of Cawdor, who had taken part in Norwegian campaigns against his own king, Duncan of Scotland, is here reported executed for his treason. This is quite convenient for the valorous Macbeth, who thus inherits the former thane's title, as the three witches had predicted [see THE MILK OF HUMAN KINDNESS and CHANCE MAY CROWN ME].
Malcolm, one of the king's two sons, pictures the erstwhile Cawdor's histrionic repentance at the gallows. "Nothing in his life," moralizes Malcolm, "became him" (reflected as well on his character) like his pious loyalty on the verge of execution. Shakespeare's audience did not have to strain their imaginations to visualize the scene; the same sort of spectacle was not unknown early in the reign of King James. James delighted in such groveling mea culpas, but unlike Duncan sometimes rewarded the groveler with his life.