Jesus often used examples from daily work and events to illustrate spiritual truths. One such example was the process of threshing and winnowing grain. The commonly grown grains in first-century Palestine were wheat and barley. At harvest, the plants were cut close to the ground by hand, bundled, and then carried to the threshing floor, which was a large flat surface of rock or hard-packed birds earth, usually at the edge or gate of the village. Sometimes the threshing floor was owned by an individual or family, sometimes by the town itself. The people spread the stalks on the threshing floor and separated the grain from the stalks. Sometimes they beat the grain with flails; sometimes they walked animals over the grain to trample it underfoot; sometimes they harnessed animals to heavy sleds or rollers that were hauled over the grain. The beating or trampling or mashing of the grain continued until all the kernels were separated from the stalks.