Saul also sent messengers unto David’s house, to watch him, and to slay him in the morning: and Michal David’s wife told him, saying, If thou save not thy life to night, to morrow thou shalt be slain.
Saul sent people to keep an eye on David's home and kill him in the morning. Michal, David's wife, warned him that if he didn't protect himself that night, he would be killed the next day.