1 Samuel 19:11

To slay him in the morning: why not in the night? Answ. Partly, because it would have been barbarous, and most dishonourable to Saul, to break into David's house by night, and kill him in his own house and bed; and it seemed more expedient to kill him as he came out of his house in the morning; partly, because the night might give David some opportunity of escaping, which the day-light would prevent; and principally, by God's singular providence, infatuating Saul's mind to take the worst course, that David might be delivered from him. Tomorrow thou shalt be slain; which she might learn, either by information from Jonathan, or some other courtier that was privy to rite design; or from her own observation of some suspicious or dangerous persons hovering about the house.