Charles H. Spurgeon on Psalms 69:15

Let not the waterflood overflow me. He continues to recapitulate the terms of his lament. He is willing to bear suffering, but entreats grace that it may not get the victory over him. He was heard in that he feared. Neither let the deep swallow me up. As Jonah came forth again, so let me also arise from the abyss of woe; here also our Lord was heard, and so shall we be. Death itself must disgorge us. Let not the pit shut her mouth upon me. When a great stone was rolled over the well, or pit, used as a dungeon, the prisoner was altogether enclosed, and forgotten like one on the oubliettes of the Bastille; this is an apt picture of the state of a man buried alive in grief and left without remedy; against this the great sufferer pleaded and was heard. He was baptised in agony but not drowned in it; the grave enclosed him, but before she could close her mouth he had burst his prison. It is said that truth lies in a well, but it is assuredly an open well, for it walks abroad in power; and so our great Substitute in the pit of woe and death was yet the Conqueror of death and hell. How appropriately may many of us use this prayer. We deserve to be swept away as with a flood, to be drowned in our sins, to be shut up in hell; let us, then, plead the merits of our Saviour, lest these things happen unto us.