600. Friday Labors That Continue on Shabbos

Shabbos 3:2

Examples of beginning an act of labor before Shabbos that continue on their own on Shabbos: we may open a channel of water to irrigate a garden on Friday that will continue to run on Shabbos. We may place a censer of incense under clothes that will continue to make them fragrant on Shabbos. We may apply ointment to an eye or a bandage to a wound that will continue the healing process on Shabbos. We may mix ink and herbs before Shabbos and let the mixture steep on Shabbos. We may place wool into a vat of dye or bundles of flax into an oven so that color change continues on Shabbos. We may lay out traps for animals, birds and fish before Shabbos that will continue to capture prey on Shabbos. We may load an olive press or a wine press before Shabbos that will continue to squeeze out the liquids on Shabbos. Similarly, we may light a candle or a fire before Shabbos that will continue burning on Shabbos.

Shabbos 3:3

A pot may be placed on a fire and meat may be placed in the oven or over coals before Shabbos so that they continue to cook on Shabbos so long as the food in question will be eaten on Shabbos. In this situation, however, there are certain limitations that the Sages enacted to prevent a person from raking the coals on Shabbos.