Are we supposed to know which transgressions are light or severe?

Question

I remember learning that we cannot know which commandments are more important than which others -- God gave them all to us and we don't say that we prioritize some over others (aside from the special priority to save a person's life). Avot 2:1 touches on this, saying to be as careful with a light commandment as with a grave one because we don't know their rewards. And I know we're not supposed to interrupt the performance of a mitzvah to do a different mitzvah, so we don't apply priorities there.

Yoma 8:8 teaches:

Repentance effects atonement for light transgressions: [the transgression of] positive commandments and negative commandments. And for severer transgressions [repentance] suspends [the divine punishment], until Yom HaKippurim arrives and effects atonement.

Is the mishna speaking in the abstract, saying that for some unspecified transgressions you can atone immediately and for others you have to wait until Yom Kippur? Or, when it says "light transgressions" (עֲבֵרוֹת קַלּוֹת), are we supposed to understand which those are? I understand the passage in Avot to be saying "commandments you think are light (or grave)", but maybe that's a misunderstanding?

Answer 1

Bartenura in Yoma explains (based on the gemara to this mishnah) that ‘light’ commandments here means all positive mitzvot as well as negative mitzvot which are able to be subsequently ‘fixed’ (lav hanitak le’asei). ‘Severe’ transgressions includes the bulk of negative mitzvot (and within that set the gemara differentiates further depending on certain factors e.g. whether they are punished by karet or not).

Bartenura in Avot explains that mishnah to mean that we are unable to ascertain the relative severity of positive mitzvot, but when it comes to the negative mitzvot we are indeed able to ‘rank’ them based on their prescribed punishments.

Answer 2

I'm glad you asked about the punishment (and the resulting Teshuvah) as the measure of a Mitzvah's severity. Rambam clearly explains it in Teshuva 1, 4:

יֵשׁ עֲבֵרוֹת שֶׁהֵן מִתְכַּפְּרִים לִשְׁעָתָן וְיֵשׁ עֲבֵרוֹת שֶׁאֵין מִתְכַּפְּרִים אֶלָּא לְאַחַר זְמַן, כֵּיצַד:
-עָבַר אָדָם עַל מִצְוַת עֲשֵׂה שֶׁאֵין בָּהּ כָּרֵת וְעָשָׂה תְּשׁוּבָה אֵינוֹ זָז מִשָּׁם עַד שֶׁמּוֹחֲלִין לוֹ, ...
-עָבַר עַל מִצְוַת לֹא תַּעֲשֶׂה שֶׁאֵין בָּהּ כָּרֵת וְלֹא מִיתַת בֵּית דִּין וְעָשָׂה תְּשׁוּבָה, תְּשׁוּבָה תּוֹלָה וְיוֹם הַכִּפּוּרִים מְכַפֵּר...
-עָבַר עַל כְּרֵתוֹת וּמִיתוֹת בֵּית דִּין וְעָשָׂה תְּשׁוּבָה, תְּשׁוּבָה וְיוֹם הַכִּפּוּרִים תּוֹלִין וְיִסּוּרִין הַבָּאִין עָלָיו גּוֹמְרִין לוֹ הַכַּפָּרָה. וּלְעוֹלָם אֵין מִתְכַּפֵּר לוֹ כַּפָּרָה גְּמוּרָה עַד שֶׁיָּבוֹאוּ עָלָיו יִסּוּרִין...
-בַּמֶּה דְּבָרִים אֲמוּרִים בְּשֶׁלֹּא חִלֵּל אֶת הַשֵּׁם בְּשָׁעָה שֶׁעָבַר אֲבָל הַמְחַלֵּל אֶת הַשֵּׁם אַף עַל פִּי שֶׁעָשָׂה תְּשׁוּבָה וְהִגִּיעַ יוֹם הַכִּפּוּרִים וְהוּא עוֹמֵד בִּתְשׁוּבָתוֹ וּבָאוּ עָלָיו יִסּוּרִין אֵינוֹ מִתְכַּפֵּר לוֹ כַּפָּרָה גְּמוּרָה עַד שֶׁיָּמוּת. אֶלָּא תְּשׁוּבָה יוֹם הַכִּפּוּרִים וְיִסּוּרִין שְׁלָשְׁתָּן תּוֹלִין וּמִיתָה מְכַפֶּרֶת.: