851. Forbidden Produce on Shabbos
Shabbos 25:18
If a rock was placed in the bucket of a well (to enable it to sink in water), then if it the rock does not fall out when water is drawn, it is considered part of the bucket and one may draw water with it. If the rock does fall out, one may not draw water with this bucket on Shabbos. A garment that is hanging on a reed may be removed from the reed on Shabbos.
Shabbos 25:19
It is prohibited to carry produce that is forbidden to eat, such as untithed produce. This is true even if the obligation to tithe the produce is only rabbinic. Other prohibited forms of produce include produce separated as first tithe, from which terumas maaser (the portion for the kohein) has not been taken, terumah that was rendered ritually unclean, and produce that was separated as second tithe or that was consecrated but that has not yet been redeemed. It is, however, permissible to carry doubtfully-tithed produce (demai) because such produce may be eaten by needy people. One may also carry produce that was separated as second tithe or that was consecrated if it has been redeemed even if the additional fifth was not added.