Once when there was a drought in Eretz Yisrael, the rabbanim approached Rabi Yochanan Ben Zakkai. “Rebbe,” they said, “please pray to Hashem that He send rain before the people perish from thirst and hunger.”
Rabi Yochanan asked that the man who cuts his hair come to see him. When the man came to the Bais Midrash, Rabi Yochanan said, “The drought is on Eretz Yisrael because the people are sinning and not doing teshuvah. Therefore, go out in the marketplace and shout: ‘My Rabi Yochanan ben Zakkai wants to take a haircut, but he is too weak to get out of bed because of the drought. He is weak from hunger.’”
When the people heard the barber’s cry, they were overcome with regret. They gathered together to cry and pray for forgiveness for their sins. Immediately thereafter, the skies were covered with clouds and rain began to fall.
How great is the power of teshuvah!