The harsh Tochachos that you hear will bring you Olam HaBah. (Rabeinu B'chayei).
Chazal say that if a person went 40 days without Yissurim he lost his Olam HaBah! The Gemara says that it’s a tremendous Zechus to listen quietly to your Rebbe’s Tochachos, and: כָּל הַמְנַבֵּל עַצְמוֹ עַל דִּבְרֵּי תּוֹרָּה סוֹפוֹ לְהִּתְנַשֵּא ברכות סג ב in the end, it will cause you to become elevated. Be happy if you suffer, and you don’t seem to do well in your learning and other areas compared to others; in the end you will become great because of this (if you keep trying).
Rabeinu B'chayei explains on the pasuk: אַתֶּּם נִּצָּבִּים הַיּוֹם כֻּלְכֶּם לִּפְנֵּי ה' אֱל קֵּ יכֶּם (כט ט) that two promises are included: Israel will always exist and will merit Olam HaBah through keeping the Torah, even though they were worthy of destruction due to the harsh rebukes. The suffering purifies them and grants them Olam HaBah.
Gemara Arakhin 16b: Anyone who goes 40 days without suffering has received his world.
Gemara Berachos 63b: The butter of Torah is found in one who expels the milk he nursed from his mother for Torah's sake. If a student is rebuked by his Rebbe and remains silent, he merits distinguishing between pure and impure blood, and between monetary and capital cases.
Story: Chassidim tell of the Sfas Emes as a child, who learned all night and slept late. His grandfather, the Chidushei HaRim, rebuked him sharply for sleeping late. The Sfas Emes listened silently, not defending himself. When asked why, he replied that he wanted to hear more Mussar, not interrupt. He pointed to the story of Bnei Gad and Bnei Reuven, who waited until Moshe finished his rebuke before explaining themselves, showing the value of hearing Mussar.
Moshe Rabeinu was extremely sharp when he gave Mussar, intending to give Klal Yisroel Zechusim and Olam HaBah through the pain of rebuke.
STORY: The S’fas Emes explained that he loved hearing rebuke and wanted the merit of being a שׁוֹמֵּ עַ תּוֹכַ חַ ת, one who listens to Mussar. Even though Moshe’s rebuke to Bnei Gad and Bnei Reuven was unfounded, they waited to hear him out before explaining themselves. Getting sharp Mussar is a precious and golden opportunity that a person should enjoy and cherish!
