Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
Psalms Chapter 30
In Psalm 30 we have the contrast between trust in prosperity even in that given of God and in God Himself. He has come in and lifted up the poor, and not left him to his foes. His favor is life. If angry, it is but for a little moment, and for the good of His saints: the favor is for ever. In the morning it is light, if heaviness endure for a night. He may let them down as to the grave's mouth, but only to show His power in infallible deliverance. He, the godly man, Israel themselves, as a people, had trusted in given prosperity. Now, in the depth of adversity, he has found Jehovah in deliverance. The power of evil overcome is better than good we may lose. It is security, and in the blessing and arms of Jehovah for us; for He is the deliverer. We see plainly here that it is a living people to be blessed on earth (Psa 30:3; Psa 30:9). And though there may be analogous mercies in all times, for there is a government of God as regards Christians, to apply it to the saints now would be a dangerous mistake. It speaks of temporal deliverance for peace in this world (compare Isa 64:7-8). No mountain, even if we own it to be made strong by Jehovah, is like Jehovah Himself, even if I am at the pit's mouth. It is my mountain for my heart when I think of it.