Charles H. Spurgeon on Psalms 121:6

The sun shall not smite thee by day, etc. A promise made with allusion unto, and application of that care which God had over his people, when he brought them out of Egypt through the wilderness, when he guarded them from the heat of the sun by a cloud by day, and from the cold and moistness of the night and moon by a pillar of fire by night. —David Dickson.