“Who will show us good.” This is not “Who will show us something good,” as if someone could show something—a “thing”—that was good and people would be satisfied. This is “good” in the sense of good that will satisfy the soul. Humans crave happiness, but although people scrap and fight over material things, in the end those things do not satisfy and do not make people happy. Humans fight for material things because we intrinsically know there is nothing inside us that can make us happy, and so we turn to things outside ourselves that seem like they would satisfy us; material things. Nevertheless, material things never satisfy the soul—they never have and they never will, and one would think humans would know that by now. “Our intellectual nature craves the true. Our moral nature craves the right. Our sympathetic nature calls for love. Our conscious weakness and dependence call for strength from another” (The Pulpit Commentary). But people who are driven by their animal nature and desires cannot bring themselves to humbly come to God and follow His ways and actually experience the good—His good. So they continue to cry out, ‘Who will show us good” while ignoring the good from God that is within their grasp. The Psalmist knows the answer: “O Yahweh, lift up upon us the light of your face.”
“lift up upon us the light of your face.” An idiom meaning “let your face shine upon us,” or “smile upon us,” that is, show us your favor. This is a similar blessing to the one Moses spoke over Aaron and his sons in Numbers 6:25-26: “Yahweh make his face to shine on you, and be gracious to you. Yahweh lift up his face toward you, and give you peace.” The ancients were very sensitive to how a person’s face looked, in part because it was often the only part of the person that was not covered by clothing. They understood that when a person was happy, their face shone, and that is reflected in the blessing.