Rabbi Tzvi Yehuda Kook related the following story:

While living in Boisk, Rav Kook and his family would occasionally take a late summer vacation at the Dobeln summer resort along the Baltic seashore. There, he used to meet Rabbi Zelig Reuven Bengis, and the two would spend time together in the hotel and its surrounding woods.

Near the Dobeln beach, a small structure was designated as a makeshift synagogue, where the bathers would gather for Mincha and Ma'ariv — the afternoon and evening prayers. One day, Rabbi Bengis had a yahrtzeit for one of his parents, and he wanted to lead the prayers, as is customarily done. However, only nine men showed up, making them one short of a minyan (a religious quorum). One of the men, a go-getter by nature, went outside to find a tenth for the minyan. As it happened, a rather domineering man of means also had yahrtzeit that day, and he was arranging his own minyan outside. Not noticing how many men were outside, the 'go-getter' asked one of them to come inside and join Rabbi Bengis' minyan, where Rav Kook was also waiting.

Unfortunately, the outside group had numbered exactly ten, and now they were short a minyan. (When Rabbi Bengis retold the story, he explained that he had no idea that this Jew was the tenth man in the other minyan, otherwise he would never have allowed this to happen.) When the domineering man realized what had happened, he stormed into the room where Rabbi Bengis was praying and berated him with a barrage of curses and insults.

When Rav Kook saw the humiliation of this great Torah scholar, he immediately approached the assailant and gave him a resounding slap across the face. "In my presence," he said firmly, "no one degrades a Torah scholar!" 

The wealthy man was so angered that he summoned Rav Kook to court. Indeed, the news of a rabbi slapping someone across the face made a shocking impression on everyone who heard about it.

When Rav Kook returned to Boisk, some of his devoted followers approached him and expressed concern over the fact that he might be taken to prison. In an effort to avoid this, they advised him to apologize to the man and beg forgiveness for slapping him. Rav Kook, however, refused to do so. He explained,

"Concerning my own honor, I am permitted to forgive and forget. In fact, I am obligated to be humble and forbearing, as we say in our prayers, 'Let my soul be like dust to everyone.' However, if I apologize to this man, I am, in effect, condoning the affront to that great Torah scholar and consequently, the desecration of the Torah's honor."

Quite unexpectedly, the domineering man showed up at Rav Kook's door a short while later and begged forgiveness from the Rav! Thus the whole incident came to an end ... for the time being, at least.

The Gold Watch

Many years later, when Rav Kook was on a trip to the United States, a man came up to him and announced that he was the one whom the Rav had slapped in Dobeln.

He then pulled out a golden watch from his pocket and said, 'I give you this, O honored Rav, in return for the slap that you gave me. You see, that whole incident brought me nothing but disgrace. I was so humiliated that I left town and came to America, where I became extremely wealthy. Thus, my good fortune is all thanks to you.'

Rav Kook refused to accept the gift, but the wealthy man would not take 'no' for an answer. He kept on insisting until Rav Kook finally agreed to take the watch. Yet, Rav Kook still had misgivings. He felt very uncomfortable about accepting this gift and benefiting, in some way, from the humiliation of a Torah scholar.

Some time later, there was a knock on the Rav's door, and in came an old man with a heartrending story. A close relative had fallen gravely ill, and the old man needed a large sum of money in order to transfer the patient from his home to a hospital.

Rav Kook searched his drawers, but found only small change. What did he do? He took his precious gold watch and said to the man: 'Use this watch as a pledge, and you will surely receive a sizeable loan in no time. Then, with God's help, I will try to raise enough money to redeem the watch from the money-lender.'

The old man hurried off to a well-known financier, who was close to Rav Kook, and asked him for an urgent loan against the security of the golden watch. The wealthy financier looked at the watch and immediately recognized it as the Rav's. Without delay, he gave his visitor loan; and the next day, he returned the precious watch to Rav Kook.

(from 'An Angel Among Men' by R. Simcha Raz, translated by R. Moshe Lichtman, pp. 76-78)