1 Samuel 28:20
Then Saul fell straightway all along on the earth, and was sore afraid, because of the words of Samuel: and there was no strength in him; for he had eaten no bread all the day, nor all the night. Then Saul fell straightway all along on the earth, and was sore afraid, because of the words of Samuel: and there was no strength in him; for he had eaten no bread all the day, nor all the night.
The verse takes place as the Philistine army threatened Israel, when Saul felt alone and defenseless because God had forsaken him, so that the sight of the Philistine host made his heart tremble. Upon hearing the announced fate of himself and his sons, he fell full length to the earth, overcome with fear, terror, confusion and weakness, with no strength left in him. That lack of strength reflected that he had eaten nothing all day and night, being worn out with fasting, and he was also distressed by his conscience.
After the sorceress and his servants urged him, he ate the food she prepared in her cave, where he had sought counsel from a spirit, before going out to the battle in which he expected to die. The words that left him terrified were not spoken by Samuel, who remained at rest in the grave, but by Satan impersonating Samuel as a counterfeit presented through the woman of Endor, so Saul was seeking counsel from a familiar spirit rather than from the Lord. The prediction of his end was accurate, yet it was a deception used to turn Israel further from God by opening a way for them in rebellion to be instructed by Satan's cunning and thus sever the last link holding them to God.
His consultation was his final break with God, sealing a separation he had already chosen through persistent wickedness. Having let Satan lead him as a willing captive, won cautiously at first with perceptions blunted until he could be led into crime, he was now fully in the snare while Satan spread his fate before him and exulted in his confusion. The episode shows deceptive communication presented as contact with the dead, whose voices are lying words rather than genuine communion between the dead and the living.