וַיֹּאמְר֥וּ עַבְדֵֽי־שָׁא֖וּל אֵלָ֑יו הִנֵּה־נָ֧א רֽוּחַ־אֱלֹהִ֛ים רָעָ֖ה מְבַעִתֶּֽךָ׃
And Saul’s servants said unto him: ‘Behold now, an evil spirit from God terrifieth thee.
Read halakhic rulings (Jewish law) on I Samuel 16:15: and classical halakhic sources.