Shabbat 68a and Shabbat 68b, beginning Kelal Gadol, a chapter about the various melakhot of Shabbat, starting with the question of kinds of violations of Shabbat, incurring different numbers of korban hatat to atone for the sin. The Gemara here introduces the concept of tinnok she-nishbah, someone who grew up among those with no concept of Shabbat, as part of tracing how much knowledge one has to have to be considered somewhat liable for a failure to observe Shabbat.
