Olive tree

The olive (Olea europaea) is the most consequential tree in biblical agriculture. It needs little water, tolerates rocky soil, and lives for centuries; some trees in the garden of Gethsemane today have measurable roots that may go back to the Roman era. Its oil was a household staple — burned in clay lamps, mixed into bread dough, used to clean wounds, anointed onto the heads of priests and kings as a sign of divine appointment. The harvest comes in late autumn. Branches are beaten with long sticks to dislodge the fruit; whatever clings to the upper twigs is left for the poor and the stranger to glean (Deu.24.20). The fruit is pressed twice — a cold first pressing yields the cleanest oil, used for lamps in the temple; later, heavier pressings yield cooking and washing oils. Paul reaches for the olive in Romans 11 to picture the long covenant story: a cultivated olive (Israel) with some branches broken off and a wild branch (the Gentiles) grafted in — a graft that runs against normal horticulture (wild into cultivated, not the other way) and that warns the grafted branch never to boast against the root.