The Song of Miriam is still echoing in the heads of the Hebrews, just after God rescues them from the Egyptian Army, so that Egypt never again threatens them again, and three days later, they murmur against Moses and God; again, now for the second time. They reach an oasis, but the waters are bitter and not drinkable. Moses cries to God and is shown a tree which Moses throws into the water to make it sweet. What are we to make of this? We hear from St. Ambrose, Tertullian, Origen, St. Jerome and Cyril of Alexandria for insight into these events.