Paul applies the allegory in the previous chapter by reminding the believers to use their liberty in Christ because all the law is fulfilled in loving neighbors as ourselves.
"It is so that we can be free that Christ has set us free." It is implied that Christ sets believers free from the old covenant. Here freedom from the old covenant is a metaphor for not being obligated to obey it. Alternate translation: "Christ has set us free from the old covenant so that we might be free" or "Christ has set us free so that we might live as free poeple" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/figs-metaphor]])
Standing firm here represents being determined not to change. How they are not to change can be stated clearly. Alternate translation: "Do not give in to the arguments of people who teach something else" or "Be determined to stay free" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-explicit]])
Here being under control of a yoke of slavery represents being obligated to obey the law. Alternate translation: "do not live like one who is under the control of a yoke of slavery to the law" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-explicit]])