Charles H. Spurgeon on Psalms 121:7

The Lord shall preserve thee from all evil. Lawyers, when they are drawing up important documents, frequently conclude with some general terms to meet any emergency which may possibly occur. They do this on the principle, that what is not in may be supposed to be intentionally left out. In order to guard against this inference, they are not content with inserting a number of particular cases; they conclude with a general statement, which includes everything, whether expressed or not. A similar formula is inserted here. It is of great Importance, that the feet of travellers be kept from sliding, as they pursue their journey. It is of great importance, that they be preserved from heat by day, and from cold by night. But other dangers await them, from which they require protection; and lest the suspicion be entertained, that no provision is made for these being surmounted, they are all introduced in the saving and comprehensive clause. No matter what may be their character, no matter from what quarter they may appear, no matter when they may nome, and no matter how long they may continue, the declaration covers them all. Divine grace changes the nature of everything it handles, and transforms everything it touches into gold. Afflictions are overruled for good; and the virtues of the Christian life are developed with unusual lustre. "The Lord shall preserve thee from all evil." —N. McMichael.