Out of the depths have I cried unto Thee, O LORD. Lord, hear my voice: let Thine ears be attentive to the voice of my supplications….I wait for the LORD, my soul doth wait, and in His word do I hope…Let Israel hope in the LORD: for with the LORD there is mercy, and with Him is plenteous redemption… – Psalm 130

When we meet with a man who has been in special trouble, and he has escaped from it, we are anxious to know how it came to pass, in order that, if we are cast into similar trial, we also may resort to the same door of hope. You meet with a man that has long been sorely afflicted, and to find him full of joy at his relief is a pleasure and a personal comfort. You heard him lamenting for years, and now you hear him rejoicing; and this excites your wonder and your hope. It is as though a cripple saw another lame man leaping and running. He very naturally enquires, “How is this?” The other day you saw a man blind, begging in the street, and now he has an eye bright as that which sparkles on the face of a gazelle, and you cry in astonishment-“Tell me who was the oculist that operated on your eyes; for I may be in a like case, and I should be glad to know where to go.” Here, then, we have a gate of knowledge opened before us. The Psalmist found salvation and deliverance in going direct to God, and trusting in Him; let us follow his example, and in all times of distress, caused by our own iniquity, or by anything else, let us repair to the throne of grace; for the Most High will deal with us also even as He dealt with His servant of old time, to whose cries, out of the depths, He lent an attentive ear. This psalm is called “De Profundis”; its teaching is not only profound but practical. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2199.cfm