Student of the Maggid of Mezritch.
Student of the Maggid of Mezritch, founder of the Belarus Chassidic movement and the Karlin-Stolin Chassidic dynasty. He is also called Rabbi Aharon The Great.
Rabbi Aharon visited many Jewish communities and according to the great rabbis of his generation, he influenced tens of thousands of Jews to do tshuvah (repentance).
IN ALL MY HOUSE, HE IS TRUSTWORTHY
Rabbi Aharon of Karlin once entered the study of his rebbe, Rabbi Dov Ber (the Maggid of Mezritch), to take his leave, for he wished to go home. The rebbe parted with him. But as soon as Rabbi Aharon left the room, the rebbe sent a few of his "holy company" to stop Rabbi Aharon from leaving. They stopped him, and so Rabbi Aharon returned to R' Dov Ber to again ask permission to leave. And so again the rebbe saw him off, and again he sent a few of his students to prevent him from leaving. And this took place a few more times. Finally, Rabbi Aharon ignored what the students were telling him. He said to them, "If the rebbe didn't want me to go home, he would have told me himself." And he went home.
And there, he immediately passed away.
Greatly pained by Rabbi Aharon's death, the students took courage and went to ask Rabbi Dov Ber why he had given Rabbi Aharon permission to leave. In response, the rebbe sent them to his oven stoker who would later be known as Rabbi Zusha of Anipoli.
Rabbi Zusha answered them as follows:
The Torah praises Moshe by saying that "in all My house he is trustworthy." But what does it mean that someone is trustworthy in God's house? Is there anything there that could be stolen? The answer is that Moshe would not tell what he had seen in heaven unless he was given permission to reveal it. The Midrash teaches that Moshe knew with certainty from heaven that if all the people prayed for him, the decree that he cannot enter the Holy Land would be nullified. He hinted at this many times. But since they did not understand, he did not openly tell them this secret, even though it was for his own sake (Devarim 3). And so you must understand that although the rebbe knew everything in advance and looked for ways to keep Rabbi Aharon from going home, he could not say anything openly.
(Chasidishe Maasiyos, p. 77)
Rabbi Aharon died at the early age of 36. He left behind a righteous son Rabbi Asher of Stolin who was the father of the famous tzaddik Rabbi Aharon Karlin II.
Today, Karlin-Stolin Chassidim are a dynamic force in the Torah world, maintaining outstanding yeshivot in Jerusalem, Teveria, Brooklyn, and other cities.
May the merit of the tzaddik Rabbi Aharon of Karlin I protect us all, Amen.