Kiddushin 31 - Honoring one's Parents
Rabbi Tarfon had an elderly mother whom he treated with such respect that whenever she wanted to climb into bed, he would bend down and she would climb on him into it; and whenever she descended, she would descend on him to reach the floor.
Rabbi Tarfon came and lauded his own performance of the mitzvah to his colleagues in the study hall. They told him: You have not yet reached half of the honor one can bestow upon his parents. Has your mother ever thrown a bag of money into the sea in your presence and you did not shame her?