The conflict between Saul and David reaches a new level of intensity, shifting from open attacks to a calculated siege on David's home. Saul dispatches men with a twofold mission: to keep watch over the house to prevent David from escaping under the cover of darkness, and to execute him the following morning. This delay raises a clear question. If the goal was to eliminate David, why did Saul instruct his men to wait until dawn rather than acting immediately in the night?
Several factors contributed to this decision. On a personal level, Saul wanted to avoid executing David in front of his daughter Michal [רד"ק]. Practically, a nighttime assassination carried the risk that David might use the darkness to outsmart his attackers and slip away [רלב"ג]. Additionally, Saul might have hoped that David would provoke a physical struggle with the guards surrounding his home. If David died while resisting, he would be blamed for his own death [מלבי"ם].
However, the primary approach among commentators is that Saul delayed the execution for political reasons, carefully managing his public image. Knowing that David was completely innocent, Saul feared the public backlash of killing him openly without a valid legal reason [מצודת דוד, רלב"ג]. Therefore, he needed a way to mask the murder. One strategy was to bring David to the palace in the morning just like any other day. Once there, Saul could kill him through a sudden trick, such as throwing a spear, making the act appear as a fit of sickness or an evil spirit rather than a calculated murder [מצודת דוד, רלב"ג].
Another aspect of this deceit involved using the siege to manufacture a legal excuse for the execution. The guards were placed at night not only to prevent an escape, but to stop people from claiming that David had stayed in his home innocently and had not tried to flee. The tight security was designed to frame David, allowing Saul to judge him as a rebel who left without permission, thereby presenting a public facade of a fair and just trial [מלבי"ם].