Mishnayos Parah Perek 7 Mishnah 12

One who broke down a fence [even] with the intention of putting it up again, the water remains valid; But if he put a fence up, the water becomes invalid. If he ate figs intending to store some of them, the water is valid; But if he stored figs it is invalid. If he was eating figs and, leaving some over, threw what was in his hand under the fig tree or among drying figs in order that it shall not be wasted, the water is invalid.