Here "listen" means to obey, and "them" refers to Yahweh's commandments. The full meaning of this statement can be made explicit. Alternate translation: "listen to Yahweh's commandments, statutes, and decrees" (See: [[rc://en/ta/man/translate/figs-explicit]])
This is an idiom. Alternate translation: "a land where plenty of milk and honey flow" or "a land that is excellent for cattle and farming" (See: [[rc://en/ta/man/translate/figs-idiom]])