The Hamlet Project

Is this what the king was gunning for in that epic speech about people changing their tunes later? Was he aiming to get a MORE binding oath out of his wife?
Was all that stuff about the discrepancy between thought and acting actually just a play to get her to swear herself into a corner?
I suppose that might give the King something to play in that excessively long list of aphorisms.
This line, then, becomes a button on his having won the thing he wanted.