Albert Barnes 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)

For the Lord has poured out upon you - The word translated ‘has poured out’ (נסך nâsak) is usually referred to the act of pouring out a libation, or drink-offering, in worship (Exodus 30:9; Hosea 9:4; Isaiah 30:1). Here it means that Yahweh had, as it were, “drenched them” (Septuagint, πεπότικε pepotike) with a spirit of stupefaction. This is attributed to God, in accordance with the usual custom in the Bible, by which his providential agency is recognized in all events (see the notes at Isaiah 6:9-10). Compare the notes at Romans 11:8, where this passage is quoted from the Septuagint and is applied to the Jews in the time of the apostle Paul.

The spirit of deep sleep - The word translated ‘deep sleep’ is the same as is used in Genesis 2:21 to denote the sleep that God brought on Adam; and in Genesis 15:12 to denote the deep sleep that fell on Abraham, when a horror of great darkness fell upon him; and in 1 Samuel 26:12 to denote the deep sleep that came upon Saul when David approached and took away the spear and the cruse of water from his bolster. Here it means spiritual sluggishness, inactivity, and stupidity, which prevailed everywhere among the people regarding religious matters.

The seers - Those who see visions, another name for the prophets (see the note at Isaiah 1:1).

Has he covered - That is, he has covered their eyes, or they are all blind.