Parashas Acharei Mos · Passuk 18:29
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “The souls that do” — those who perform the act incur karet; those who only approach do not incur karet.
Karet for the act, not mere approach
Although “do not approach” is forbidden, the penalty of karet attaches only to the completed act.