What does Isaiah 8:19 mean?

When people tell you, 'Go ask those who talk to the dead and consult spirits—people who whisper and mutter,' shouldn't a nation turn to their God instead? Why ask the dead for help for the living? Isaiah 8:19 - Modern Text Bible

(Isaiah warns against seeking answers from mediums or spiritists. He urges people to look to God, not to the dead, for guidance.)