주려무나 and 주렴 are a weak form of an imperative ending. They suggest that someone do something, like "Why don't you..." in English. They are always used only with familiar people or someone younger than you. 거울아 거울아 제발 좀 말해주려무나: Mirror, mirror, can't you please tell me. 좋을 대로 하렴: Why don't you do as you like?