Midrash su Levitico 23:29

4) (Vayikra 23:29) "For every soul which will not be afflicted on this self-same day will be cut off from its people." This is the punishment for (non-) application. (Vayikra 23:30) "I shall make that soul go lost": What is the intent of this? (i.e., What do we learn from this equivalence between kareth ["cutting-off"] and "aveidah" ["going lost"]?) Because "kareth" is mentioned in every place and I do not know what it is, "I shall make that soul go lost" indicates that "kareth" refers to complete destruction (and not merely to the cutting off of the soul from the body.) And whence is it derived that eating, drinking, washing, anointing, cohabitation, and shodding are forbidden on Yom Kippur? From (Vayikra 23:32) "A Sabbath of resting … and you shall afflict" (The connotation is extension of affliction). I might then think that all of these are forbidden on the Sabbath of creation (i.e., Saturday, which is also referred to as "a Sabbath of resting"); it is, therefore, written "A Sabbath of resting it (Yom Kippur) shall be for you and you shall afflict, etc." "It" is forbidden in all (of these things), and not the Sabbath of creation.

8) I might think that there is no kareth liability for labor (on the addition), but that there is such liability for (non-) affliction on the addition; it is, therefore, written (Vayikra 23:29) "For every soul which will not be afflicted on this self-same day will be cut off." For (non-) affliction on the self-same day there is kareth liability, but not for (non-) affliction on the addition. I might think that he is not subject to the punishment, but that he is subject to (transgression of) the exhortation. It is, therefore, written "All work you shall not do on this self-same day." There is exhortation against (labor on) this self-same day, but not against labor on the addition.