The word "Joseph" refers to the nation of Israel. Asaph speaks of the people as if they were a flock of sheep that Yahweh, who is the shepherd, leads. Alternate translation: "you who lead the descendants of Joseph as though they were a flock of sheep" (See: [[rc://en/ta/man/translate/figs-metaphor]])
You may need to make explicit that the cherubim are those on the lid of the ark of the covenant. The biblical writers often spoke of the ark of the covenant as if it were Yahweh's footstool upon which he rested his feet as he sat on his throne in heaven above. Alternate translation: "you who sit on your throne above the cherubim on the ark of the covenant" (See: [[rc://en/ta/man/translate/figs-explicit]])
Asaph speaks of God as if he were the sun, giving light, a metaphor for moral goodness. Alternate translation: "give us light" or "show us the right way to live" (See: [[rc://en/ta/man/translate/figs-metaphor]])