John Gill Commentary 1 Samuel 28:22

"Now therefore, I pray thee, hearken thou also unto the voice of thy handmaid, and let me set a morsel of bread before thee; and eat, that thou mayest have strength, when thou goest on thy way." — 1 Samuel 28:22 (ASV)

Now therefore, I pray you, listen you also unto the voice
of your handmaid
She argues, that as she had listened to him to the endangering of her life, it was but reasonable, and might be expected, that he would listen to her in a case that would be to the preservation of his life:

and let me set a morsel of bread before you, and eat, that you may
have strength, when you go on your way ;
She might urge, not merely out of respect to the king, but for her own sake, lest should he die in her house, she might be taken up, not only for a witch, but as being accessory to the death of the king; and therefore she moves, that he would take some food for refreshment of nature, that he might be able to depart her house, and go on her way to his army.