They look up, but not in hope. What does this desperate gesture reveal about their hearts?
The final phrase, 'and turn their faces upward,' is crucial. It's not a hopeful gaze towards heaven for relief. The commentaries consistently point out this look is filled with despair, defiance, and perhaps even a sarcastic plea.
No True Refuge
These individuals have rejected God's counsel (implied by the context of Isaiah 8:20, 'to the law and to the testimony'). Now, in their deepest distress, they look upward, but they see only the 'dimness of anguish' (as JFB notes) – a reflection of their own inner darkness and God's perceived, but misunderstood, displeasure. Their upward look is an admission of their dire straits, but without the faith to find true rescue.