Rav Dovid Sperber, the Brashov Rav z”l, related the following story: One rav would often visit Maran Rebbe Yissochor Dov of Belz zy”a. When that Rav became very elderly, at the age of over ninety years, he stopped coming to Belz, which surprised many of his friends. When he was asked why, he related the following: “I would always travel to Belz to be with the Rebbe. Once when the Rebbe conducted his Shabbos tish, I noticed that when he wanted to cut the challah, it was very hard for him, because the knives hadn’t been sharpened properly and he had to separate the challah with his hands. So in honor of the forthcoming Shabbos, I sharpened the knives properly, and the following week the Rebbe was able to cut the challah with ease. During the tish, the Rebbe asked, who had sharpened the knives? I didn’t say a word out of fear that he might have an hakpodo on me why I did it. When the Rebbe asked again and no one answered, he said: “I promise that whoever sharpened the knives will merit longevity.”

When the Rav finished telling his story, he said: “I am already 95, and all of the burdens of my grandchildren and great grandchildren fall upon me, having to listen to all of their woes and tzoros. But I have no strength to hear all that. I suspect that if I will travel to Belz the Rebbe will add some more years to my life which I don’t want.”

[Tiferes Bonim II (s. 72) on Kitzur Shulchan]