John Calvin Commentary Isaiah 29:10

"For Jehovah hath poured out upon you the spirit of deep sleep, and hath closed your eyes, the prophets; and your heads, the seers, hath he covered." — Isaiah 29:10 (ASV)

Because Jehovah has overpowered you with the spirit of slumber. To show more clearly the source of this blindness, he attributes it to the judgment of God, who determined to punish the wickedness of the people in this manner. Just as it is His role to give eyes to see and to enlighten minds with the spirit of judgment and understanding, so He alone deprives us of all light when He sees that, through a wicked and depraved hatred of the truth, we willingly choose darkness. Accordingly, when people are blind, especially in matters so plain and obvious, we perceive His righteous judgment.

Your prophets and principal seers. He adds that the people are deprived of those aids and helps that should have imparted light to the understanding and given direction to others. Such was the office of the prophets, whom he describes by both of these names, נביאים (nēbīīm) and חזים (chōzīm), “prophets” and “seers.” In short, he means that not only will people endowed with reason and understanding be deprived of common sense, but their teachers also—whose duty it was to enlighten others—will be utterly senseless. They will not know the way; covered with the darkness of ignorance, they will shamefully go astray. They will be so far from directing others that they will not even be able to guide themselves.