Charles H. Spurgeon on Psalms 104:29

They are troubled. They are confounded; they are overwhelmed with terror and amazement. The word "troubled" by no means conveys the sense of the original word —Nab, bahal —which means properly to tremble; to be in trepidation; to be filled with terror; to be amazed; to be confounded. It is that kind of consternation which one has when all support and protection are withdrawn, and when inevitable ruin stares one in the face. So when God turns away, all their support is gone, all their resources fail, and they must die. They are represented as conscious of this; or this is what would occur if they were conscious. Albert Barnes.