Macbeth scene 3 what does this line mean chance will have me king why may crown without my stir?

The line "chance will have me king, why may crown without my stir" from Macbeth's soliloquy in scene 3 means that if fate intends for him to become king, then he does not need to take any action to make it happen. He believes that if it is his destiny, then it will come to pass without his intervention.