Charles H. Spurgeon on Psalms 23:6

The psalmist expresseth an exceeding confidence in the midst of most inexpressible troubles and pressures. He supposes himself "walking through the valley of the shadow of death." As "death" is the worst of evils, and comprehensive of them all, so the "shadow" of death is the most dismal and dark representation of those evils into the soul, and the "valley" of that shadow the most dreadful bottom and depth of that representation. This, then, the prophet supposed that he might be brought into. A condition wherein he may be overwhelmed with sad apprehensions of the coming of a confluence of all manner of evils upon him —and that not for a short season, but he may be necessitated to "walk" in them, which denotes a state of some continuance, a conflicting with most dismal evils, and in their own nature tending to death —is in the supposal. What, then, would he do if he should be brought into this estate? Saith he, "Even in that condition, in such distress, wherein I am, to my own and the eyes of others, hopeless, helpless, gone, and lost, 'I will fear no evil.'" A noble resolution, if there be a sufficient bottom and foundation for it, that it may not be accounted rashness and groundless confidence, but true spiritual courage and holy resolution. Saith he, "It is because the Lord is with me." But alas! what if the Lord should now forsake thee in this condition, and give thee up to the power of thine enemies, and suffer thee, by the strength of thy temptations, wherewith thou art beset, to fall utterly from him? Surely then thou wouldst be swallowed up for ever: the waters would go over thy soul, and thou must for ever lie down in the shades of death. "Yea," saith he, "but I have an assurance to the contrary; 'Goodness and mercy shall follow me all the days of my life.' John Owen.