When Reb Yaakov Kaminetzky ZT”L came to America, he was a meshulach for the Kovna kollel. He stopped in to visit a certain businessman, and told him that the businessman gave a certain amount of dollars last year. The businessman challenged the number, and showed Reb Yaakov ZT”L a receipt with a lower number. Reb Yaakov ZT”L quit on the spot. The guy wanted to give Reb Yaakov ZT”L a check anyway. Reb Yaakov ZT”L told him he no longer works for the kollel, and is unable to take money for them.
When Reb Moshe ZT”L came out with his psak on AI Donor, a certain kanoi went out of his way to make Reb Moshe’s life miserable. One day, this kanoi is arrested by the government for fraud. Before sentencing, this kanoi asked Reb Moshe ZT”L to write a letter to the judge in order to get a more lenient sentence. Reb Moshe ZT”L wrote the letter without hesitation. After all, a Jew needs his help.
Someone was engaged to the daughter of Reb Baruch Ber ZT”L. The guy later broke it off. Sometime after that, the guy asked Reb Baruch Ber for a recommendation letter. Reb Baruch Ber wrote the latter, and asked several people their opinion of it to make sure there was no mashehu of a violation of “lo sitor”.
Many people like to say they’re totally leshem shomayim, with no desire for personal kavod. The saintly Reb Chaim Shmuelevitz, who worked on himself his entire life, still admitted later in life that it feels good when he gets a bracha at a wedding titled “Der Rosh Yeshiva fun Der Mirrer Yeshiva”.