Midrash sur Avot 4:11
רַבִּי אֱלִיעֶזֶר בֶּן יַעֲקֹב אוֹמֵר, הָעוֹשֶׂה מִצְוָה אַחַת, קוֹנֶה לוֹ פְרַקְלִיט אֶחָד. וְהָעוֹבֵר עֲבֵרָה אַחַת, קוֹנֶה לוֹ קַטֵּגוֹר אֶחָד. תְּשׁוּבָה וּמַעֲשִׂים טוֹבִים, כִּתְרִיס בִּפְנֵי הַפֻּרְעָנוּת. רַבִּי יוֹחָנָן הַסַּנְדְּלָר אוֹמֵר, כָּל כְּנֵסִיָּה שֶׁהִיא לְשֵׁם שָׁמַיִם, סוֹפָהּ לְהִתְקַיֵּם. וְשֶׁאֵינָהּ לְשֵׁם שָׁמַיִם, אֵין סוֹפָהּ לְהִתְקַיֵּם:
R. Eliezer ben Yaakov dit: Si quelqu'un fait une mitsva, il acquiert pour lui-même un avocat de la défense [c'est-à-dire, un ange parlant en son nom.] Et si quelqu'un commet un péché, il acquiert pour lui-même un kategor (un procureur), [c'est-à-dire un ange incriminant, (kategor étant l'acronyme de «kore tigar», «appelant à des conflits». Sanegor, le contraire de kategor est l'acronyme de «sone tigar», «hainant les conflits»)] R. Yochanan Hasandlar dit: Tout rassemblement qui est pour l'amour du ciel est destiné à durer, et (tout rassemblement qui n'est) pas pour l'amour du ciel n'est pas destiné à durer.
Pirkei DeRabbi Eliezer
REPENTANCE and good deeds are a shield against punishment. Rabbi Ishmael said: If repentance had not been created, the world would not stand. But since repentance has been created, the right hand of the Holy One, blessed be He, is stretched forth to receive the penitent every day, and He says, Repent, ye children of men. "Repent, ye children of men" (Ps. 90:8). Know thou the power of repentance. Come and see from Ahab, king of Israel, for he had robbed, coveted, and murdered, as it is said, "Hast thou killed, and also taken possession?" (1 Kings 21:19). He sent and called for Jehoshaphat, king of Judah, who gave him thrice daily forty stripes, and in fasting and with prayer he rose up early and retired late, before the Holy One, blessed be He, and he did not return any more to his evil deeds. His repentance was accepted, as it is said, || "Seest thou how Ahab humbleth himself before me? Because he humbleth himself before me, I will not bring the evil in his days" (1 Kings 21:29).