The oak is a common symbol of strength and endurance.
In Greek Myth, the oak is the tree sacred to Zeus, king of the gods. In Zeus’s oracle in Dodona, the priestesses would divine the pronouncements of the god by interpreting the rustling of the oak’s leaves.
In Celtic tree lore, the oak is associated with strength, resilience and self-confidence.. The Oak King rules over the summer months, and this tree was sacred to the Druids. Mistletoe grows in oaks, and Druids ritually harvested the plant for herbal/medicinal uses.