Tohoros 9:2-3

Tohoros 9:2

If one finished harvesting his olives but he intended to buy more, or if he finished buying olives but he intended to borrow more, or if mourning, a celebration or some other mishap occurred (delaying his completion of olive-pressing), then the olives remain clean even if zavim and zavos walk on them. If ritually unclean liquids fall on them, then only the place where it touched is rendered unclean. Any liquid that the olives may exude is ritually clean.

Tohoros 9:3

When work on the olives is finished, they become susceptible to impurity. If an unclean liquid falls on them, they are rendered unclean. Rabbi Eliezer says that liquid they exude is ritually clean but the Sages declare it unclean. Rabbi Shimon says that they didn’t disagree that the liquid exuded by olives is clean. They disagreed about the liquid that remains in the vat (after the oil has been taken); Rabbi Eliezer says this is clean, while the Sages declare it unclean.