Biblical Context:
The event of Saul eating and departing into the night is found in 1 Samuel 28, a chapter that details a critical moment in the life of King Saul, the first king of Israel. This narrative occurs during a time of great distress for Saul, as he faces the impending threat of the Philistine army. The prophet Samuel, who had been a spiritual guide for Saul, has died, leaving Saul without divine counsel. In desperation, Saul seeks out a medium at Endor to summon the spirit of Samuel, an act that was against the laws he himself had enforced (1 Samuel 28:3).

Narrative Summary:
In 1 Samuel 28:20-25, after the spirit of Samuel is conjured and delivers a dire prophecy of Saul's impending defeat and death, Saul is overcome with fear and weakness. The text states, "Immediately Saul fell full length on the ground, filled with fear because of Samuel’s words. His strength was gone, for he had eaten nothing all that day and all that night" (1 Samuel 28:20). The medium, seeing Saul's distress, insists that he eat to regain his strength. Despite his initial refusal, Saul eventually consents to eat after his servants and the woman urge him.

The woman prepares a meal of a fattened calf and unleavened bread, which Saul consumes. The passage concludes with Saul and his servants rising and leaving into the night: "Then they got up and went away that night" (1 Samuel 28:25).

Theological Implications:
This episode highlights several key themes in Saul's life and reign. Firstly, it underscores Saul's spiritual decline and desperation. By seeking guidance from a medium, Saul directly disobeys God's commandments, illustrating his departure from reliance on God. This act of consulting the dead is seen as a culmination of Saul's disobedience and lack of faith, which had been evident throughout his kingship.

Secondly, the narrative emphasizes the theme of divine judgment. Samuel's prophecy, delivered through the medium, confirms that God has rejected Saul as king due to his disobedience. The prophecy foretells not only Saul's defeat but also the transfer of kingship to David, whom God has chosen as a man after His own heart (1 Samuel 13:14).

Cultural and Historical Context:
In ancient Israel, consulting mediums and necromancers was strictly forbidden (Leviticus 19:31; Deuteronomy 18:10-12). Saul's decision to seek out the medium at Endor reflects the cultural and religious tensions of the time, as well as his own internal conflict. The act of eating before departing into the night can be seen as a final moment of human weakness and resignation to his fate.

Moral and Ethical Considerations:
From a moral standpoint, Saul's actions serve as a cautionary tale about the consequences of turning away from God and seeking forbidden practices. His reliance on a medium rather than God highlights the dangers of spiritual compromise and the importance of obedience to divine commandments.

Literary Analysis:
The narrative is rich in dramatic tension, with the night setting symbolizing Saul's spiritual darkness and impending doom. The act of eating, a basic human need, contrasts with the spiritual starvation Saul experiences due to his separation from God. The departure into the night serves as a metaphor for Saul's final journey towards his tragic end, as foretold by Samuel.

Conclusion:
The account of Saul eating and departing into the night is a poignant moment in biblical history, reflecting themes of disobedience, divine judgment, and the tragic consequences of turning away from God. It serves as a powerful reminder of the importance of faithfulness and reliance on God's guidance.