'Olive tree' in the Bible

“Yet gleanings will be left in the land [of Israel] like the shaking of the olive tree,Two or three olives on the topmost branch,Four or five on the [outermost] branches of the fruitful tree,”Declares the Lord, the God of Israel.

For so it will be in the midst of the earth among the peoples,As the shaking of an olive tree,As the gleanings when the grape harvest is over [and only a little of the fruit remains].