It may be helpful to state that it is food that is given. Alternate translation: "When you give food to them, they gather it" (See: [[rc://en/ta/man/translate/figs-explicit]])
This describes Yahweh as opening his hand to give food to the creatures. Alternate translation: "when you open your hand to feed them" (See: [[rc://en/ta/man/translate/figs-explicit]])