Lady Macbeth recognizes that Macbeth's hands are bloody and still have evidence from the murder on them. She tells him to wash them off, and bring the daggers back. She wants him to place the daggers on the guards. However, Macbeth is overcome by his emotions and will not do it.
"Go get some water and wash this filthy witness from your hand" (61).
Lady Macbeth decides if her husband will not put back the daggers she will do it herself to ensure their safety to the throne. Macbeth is continuing to mourn.
"Give me the daggers" (69).
"What hands are here! Ha, they pluck out mine eyes" (77).
"To know my deed 'twere best not know thyself" (93).
Lady Macbeth has put the daggers back and she realizes that she has participated in the murder. However, she tells Macbeth that they are innocent if they just wash their hands. Then, there is knocking and they flee the scene.