Gemara

(R. Avahu): A Kal va'Chomer teaches that the fire of Gehinom does not harm Chachamim. A Salamandra (a kind of Chayah; this is the Targum of Achbar) is created from fire, and fire does not harm one who anoints with its blood. All the more so fire does not harm Chachamim, who themselves are fire - "Ha'Lo Cho Devari ka'Esh"!

(Reish Lakish): A Kal va'Chomer teaches that the fire of Gehinom does not harm Posh'ei (sinners of) Yisrael. The golden Mizbe'ach is (wood,) plated with the mere thickness of a gold Dinar, yet the fire of (coals that burn Ketores every day for) so many years never harmed it;

Posh'ei Yisrael are full of Mitzvos like a pomegranate (is full of seeds) - "K'Felach ha'Rimon Rakasech". All the more so the fire of Gehinom does not rule over them!

(Reish Lakish): We read "Rakasech" like 'Reikasayich' - even Reikim (empty Yisraelim) are full of Mitzvos like a pomegranate.

Rosh Hashanah 16b (Beraisa - Beis Shamai): There are three categories on the day of judgment. Utter Tzadikim are immediately written and sealed for eternal life. Utter Resha'im are immediately written and sealed for Gehinom - "V'Rabim mi'Yeshenei Admas Afar Yakitzu Eleh l'Chayei Olam v'Eleh la'Charafos l'Dir'on Olam".

Beinonim descend to Gehinom and scream and come up - "V'Heveisi Es ha'Shelishis ba'Esh u'Tzraftim...Hu Yikra vi'Shmi va'Ani E'eneh".

Chanah said about them "Hash-m Memis u'Mechayeh Morid She'ol va'Ya'al".

Beis Hillel say, (for Beinonim the Midah of) Rav Chesed tilts towards Chesed. About them David said the entire Parashah "Ohavti Ki Yishma Hash-m Es Koli Tachanunai...Dalosi v'Li Yehoshi'a".

Posh'ei Yisrael b'Gufam and Posh'ei Nochrim b'Gufam descend to Gehinom and are judged there for 12 months. Afterwards their body perishes, their Neshamos are burned and wind spreads the ashes under the Tzadikim's feet - "V'Asosem Resha'im Ki Yihyu Efer Tachas Kapos Ragleichem".

The following descend to Gehinom and are judged for all generations - heretics, informers and Apikorsim who denied Torah or Techiyas ha'Mesim, people who separated from the Tzibur, leaders who put excessive fear on the Tzibur not l'Shem Shomayim, and those who sinned and made others sin like Yarav'am and his colleagues,

We learn from "V'Yotz'u v'Ra'u b'Figrei ha'Anashim ha'Posh'im Bi...v'Isham Lo Sichveh".

Gehinom finishes and they do not finish - "V'Tzuram Levalos She'ol". This is because they trespassed Zevul, i.e. the Beis ha'Mikdash.

Question: Beis Hillel say that Rav Chesed tilts towards Chesed. But it says "V'Heveisi Es ha'Shelishis ba'Esh"!

Answer: That refers to Posh'ei Yisrael b'Gufam.

Question: Posh'ei Yisrael b'Gufam have no Tikun (whereas the verse says "u'Tzraftim", they are fixed)!

Answer: There is no Tikun if they were mostly Aveiros. If they are half-half, Rav Chesed tilts towards Chesed, unless their Aveiros included Posh'ei Yisrael b'Gufam. In that case, "V'Heveisi Es ha'Shelishis ba'Esh".

(Rav): Posh'ei Yisrael b'Gufam are people who never wore Tefilin. Posh'ei Nochrim b'Gufam refers to (sexual) Aveirah.

Question: How does Rav Chesed tilt towards Chesed?

Answer #1 (R. Elazar): The Midah pushes down (on the merit side of the scale) - "Yichbosh Avonoseinu".

Answer #2 (R. Yosi b'Rebbi Chanina): It lifts (the side with Aveiros) - "Nosei Avon v'Over Al Pesha".

Answer #3 (R. Yishmael): It is Ma'avir Rishon Rishon (it removes the first Aveirah, and then there will be more Mitzvos).

(Rava): The Aveirah is not erased. If in all there are mostly Aveiros, it joins with them to make the person a Rasha.

Yoma 86b - R. Yosi b'Rebbi Yehudah: If a person transgresses an Aveirah up to three times he is pardoned. From the fourth time he is not pardoned - "Hen Kol Eleh Yif'al Kel Pa'amayim Shalosh".

Kidushin 39b - R. Shimon: Even if one was a Rasha his whole life, if he repents at the end his sins are not mentioned - "The Rasha will not stumble in his evil on the day he repents from it."

Rishonim

Rif and Rosh (Rosh Hashanah 1:5): There are three categories on the day of judgment... Beis Shamai say that Beinonim descend to Gehinom and scream and come up - "V'Heveisi..." Beis Hillel say that Rav Chesed tilts towards Chesed, except for Posh'ei Yisrael b'Gufam, who descend to Gehinom for 12 months and scream and come up.

Ran (DH Tanya): This refers to "Yom Hash-m ha'Gadol veha'Nora" after Techiyas ha'Mesim. Beis Shamai say that all Beinonim descend to Gehinom and scream for a short time and come up. Beis Hillel say that Rav Chesed totally saves Beinonim from Gehinom, unless they are Posh'ei Yisrael b'Gufam. If there is any Mitzvas ha'Guf that a person never did, such as Kri'as Shma or Birkas ha'Mazon, he is called Posh'ei Yisrael b'Gufam.

Rif: If someone is mostly Aveiros, including Posh'ei Yisrael b'Gufam, which are Aveiros such as Arayos, he descends to Gehinom and is judged there for 12 months. Afterwards his body perishes, his Neshamah is burned and the ashes are spread under the Tzadikim's feet - "V'Asosem..."

Question: Above, we said that if one is mostly Aveiros he has no Tikun, even without Posh'ei Yisrael b'Gufam!

Answer (Rosh (1:5) and Ran DH Aval she'Avonoseihem): Above, it did not really mean that they are punished forever. Rather, they are punished for 12 months, and afterwards they come out. If they are Posh'ei Yisrael, after 12 months their body perishes, and their Neshamos are burned...

Heretics, informers, Apikorsim ...descend to Gehinom and are judged for generations - "V'Yotz'u..."

Ma'avir Rishon Rishon means that if a straight person stumbled in sin for the first time, Hash-m does not write it down. Rather, He removes it. This is His Midah, not to Mechayev at the beginning - "Hen Kol Eleh Yif'al Kel Pa'amayim Shalosh". A Gaon explained that R. Yishmael discusses one with Yir'as Shomayim who regularly does Mitzvos. He guards severe Mitzvos, but occasionally stumbles in a light Aveirah. The Midah of Ma'avir Rishon Rishon removes it and pardons it, and he is considered a Tzadik. The Aveirah is not erased. If he dies without Teshuvah, if he has mostly Mitzvos, the Aveiros are removed, it is as if he did not do them. If there are mostly Aveiros, they are all counted. If he died amidst Teshuvah, none of his Aveiros are mentioned - "V'Rish'as ha'Rasha Lo Yikashel Bah b'Yom Shuvo me'Rish'o". Hash-m pardons them all and puts him in the place of Tzadikim.

Ran (DH Nosei (2)): The Rif did not say how his Perush is unlike the Gaon's. It seems that the Rif holds that Hash-m overlooks the first three transgressions, unless even without them the person is mostly Aveiros.

Rambam (Hilchos Teshuvah 3:3): Just like one's deeds are weighed after death, they are weighed every year on Rosh Hashanah.

Source (Lechem Mishneh): The Rambam understands that 'there are three categories on the day of judgment...' (Rosh Hashanah 16b) refers to the day of death.

Rambam (5): When weighing Aveiros against merits, the first two Aveiros are ignored. Only Aveiros from the third and onwards are counted. If his Aveiros from the third and onwards are greater than his merits, he is judged also for the first two. If the two sides are equal, the third Aveirah is removed, for it is now first. In this way, all of his Aveiros are removed one by one.

Rebuttal (Ra'avad): The Rambam equates different matters! R. Yishmael discusses how Rav Chesed saves Beinonim from Gehinom. R. Yosi b'Rebbi Yehudah discusses pardon in this world. Normally, severe Aveiros obligate Yesurim even after Teshuvah. R. Yosi teaches that the first three Aveiros do not.

Kesef Mishneh: The Rambam explains that R. Yosi b'Rebbi Yehudah also discusses going to Gehinom or Gan Eden.

Rambam (ibid.): If a Beinoni never put on Tefilin, he is judged according to his Aveiros and he has a share in the world to come. The same applies to Resha'im whose Aveiros are greater than their merits. All Yisrael have a share in the world even if they sinned.

Rambam (6): Some have no share in the world to come. Rather, they are cut off and judged eternally for their great sins. These are heretics, Apikorsim, people who denied Torah...

Rosh (1:5): There are six categories regarding the world to come. Utter Tzadikim are immediately written and sealed for eternal life. For Beinonim without Posh'ei Yisrael b'Gufam, Rav Chesed tilts towards Chesed. Beinonim with Posh'ei Yisrael b'Gufam descend to Gehinom and emerge. If one is mostly Aveiros without Posh'ei Yisrael b'Gufam, he suffers 12 months in Gehinom then goes to the world to come. If one is mostly Aveiros with Posh'ei Yisrael b'Gufam, he suffers 12 months in Gehinom then his body perishes, his Neshamah is burned and wind spreads the ashes under the Tzadikim's feet. Tzedukim, Beisusim and informers are judged in Gehinom for all generations. The Rif's text discusses a head that never wore Tefilin. Our text does not say 'never'. It discusses one who refrained because Tefilin are disgraceful to him.

Kesef Mishneh (Teshuvah 5-6): It is a merit for ashes of Resha'im to be under Tzadikim's feet, for the Tzadikim will request mercy for them.