Charles Ellicott Commentary Isaiah 64:4

"For from of old men have not heard, nor perceived by the ear, neither hath the eye seen a God besides thee, who worketh for him that waiteth for him." — Isaiah 64:4 (ASV)

Neither has the eye seen, O God, beside You ... — The best commentators are in favor of the rendering: Neither has the eye seen a God beside You, who will work for him that waits for Him.

The sense is not that God alone knows what He has prepared, but rather that no one knows (sight and hearing being used here to include all forms of spiritual apprehension) any god who does such great things as He does.

St. Paul, in 1 Corinthians 2:9, applies these words freely, in his characteristic way, to the eternal blessings God prepares for His people. Clement of Rome (chapter 34), it may be noted, makes a similar application of the words, using those who wait for Him (as in Isaiah), instead of those who love Him.