Deuteronomy 28:28-29 -

Besides bodily ailments, mental diseases should come upon them—insanity, incapacity, confusion of mind, so that even at midday they should grope as a blind man gropes, i . e . under the most favorable circumstances they should be unable to find the right path, to hit on the right and safe course. It is of mental blindness that the word is here used (cf. Isaiah 42:19 ; Lamentations 4:14 ; Zephaniah 1:17 ; Romans 11:25 ; 2 Corinthians 4:4 ). Thou shalt grope (cf. Isaiah 59:10 ). Thus afflicted in body and mind, their state should be one only of oppression and calamity, with no hope of deliverance.