Shabbos 1:6-7

Shabbos 1:6                            

Beis Shammai say that one may not put bunches of flax in an oven on Friday unless there is enough time for them to finish steaming before Shabbos. Similarly, one may not put wool in a kettle of dye unless there is enough time for it to absorb the color before Shabbos. Beis Hillel permit these things. Beis Shammai say that one may not spread nets to catch animals, birds or fish on Friday unless they capture their prey before Shabbos; Beis Hillel permit it.

Shabbos 1:7

Beis Shammai say that one may not sell to a non-Jew on Friday, nor help him load his animal, nor place a load on him unless the non-Jew will reach his destination before Shabbos (because otherwise these things appear to be preparing to transport on Shabbos); Beis Hillel permit it.