Thou didst set them on slippery places - Affluence is a slippery path; few have ever walked in it without falling. It is possible to be faithful in the unrighteous mammon, but it is very difficult. No man should desire riches; for they bring with them so many cares and temptations as to be almost unmanageabe. Rich men, even when pious, are seldom happy; they do not enjoy the consolations of religion. A good man, possessed of very extensive estates, unblamable in his whole deportment, once said to me: "There must be some strange malignity in riches thus to keep me in continual bondage, and deprive me of the consolations of the Gospel." Perhaps to a person to whom his estates are a snare, the words of our Lord may be literally applicable: "Sell what thou hast, and give to the poor; and thou shalt have treasure in heaven: and come, take up thy cross, and follow me." But he went away sorrowful, for he had great possessions! May we not then say with the psalmist, Surely thou digest set them in slippery places, etc.?
Surely thou didst set them in slippery places - Not in a solid and permanent position; not where their foothold would be secure, but as on smooth and slippery rocks, where they would be liable any moment to fall into the foaming billows. However prosperous their condition may seem to be now, yet it is a condition of uncertainty and danger, from which they must soon fall into ruin. In their prosperity there is nothing of permanence or Stability; and this fact will explain the difficulty.
Thou castedst them down into destruction - They are placed, not in a permanent condition, but in a condition from which they will be cast down to destruction. Ruin is before them; and the end will demonstrate the justice of God. Nothing can be determined from their present condition as to the question which caused so much perplexity, but in order to a proper solution we must wait to see the end. As an illustration of this, see the interesting account of the interview between Solon of Athens, and Croesus, the rich king of Lydia, as given in Herodotus, book i., 30-33.