daf bit: Shabbat 70

A few pages back the mishna taught: He who knows that it is Shabbat and performs many forbidden labors is liable for a sin-offering for each primary category of labor. But, the g'mara points out, the torah says everyone who profanes Shabbat shall surely be put to death (Ex. 31:14), so how do you get sin-offerings at all, let alone more than one? Samuel says that is for willful transgression (he knows it is Shabbat and that the labor is forbidden). The torah also says whoever does any work (on Shabbat) shall be put to death, without the "surely", and we understand this verse to refer to unintended transgression. Because the word "surely" does not appear, we can interpret the penalty as a sin-offering instead of death as written, and sin-offerings can be multiplied. (If I am understanding this correctly.) (70a)

Today's daf (71) is part of an extended discussion about multiple instances of the same category versus multiple categories.