Rav Henoch Leibowitz at the Barber: “But He Is My Son!”
When a barber asks a Chofetz Chaim bachur if the rosh yeshiva is his father, Rav Henoch Leibowitz answers that the talmid is his son.
From the article
There was a barber shop near the yeshiva. A talmid from the yeshiva was getting a haircut when the rosh yeshiva walked in. Ralph, the barber, turned to the talmid and asked, “Is that your father?” “No,” the bachur replied. Upon hearing this, the rosh yeshiva countered “But he is my son!” The rosh yeshiva did not have any biological offspring, but the talmidim were his children.