What hasn't been seen?
There appears to be a substantial difference in meaning in Isaiah 64:4 depending on how a few words are translated--and how the sentence (in English) is punctuated:
Case 1 (example from NIV)
Since ancient times no one has heard, no ear has perceived, no eye has seen any God besides you, who acts on behalf of those who wait for him
Case 2 (example from KJV)
For since the beginning of the world men have not heard, nor perceived by the ear, neither hath the eye seen, O God, beside thee, what he hath prepared for him that waiteth for him.
(other versions supporting each of these general meanings could be cited)
One version suggests that no God but the Lord has been seen; the other version suggests that what has not been seen is what the Lord has prepared for the righteous.
Note that Paul references this idea in 1 Corinthians 2:9 as well:
However, as it is written: “What no eye has seen, what no ear has heard, and what no human mind has conceived” — the things God has prepared for those who love him—
A quick tally of modern translations appears to strongly favor Case 1. Paul's use of the passage appears to suggest Case 2.
Which is the more accurate rendering? Is Isaiah discussing seeing God or seeing what eternal life looks like?