Yes, it is recommended to soak lima beans before cooking. Soaking helps the beans cook faster and more evenly, which can prevent them from becoming mushy or breaking apart.  Soaking also helps the beans become more digestible and easier to remove from their skins. It's best to soak the lima beans in cold water for at least 8 hours, or overnight, before cooking.  Additionally, soaking may help remove some of the sugars that cause intestinal discomfort in some people when they eat legumes like lima beans. When finished soaking the beans, it's important to discard the soaking liquid and rinse them in fresh, cold water before cooking.