Joseph Telushkin said this quote

Rabbi Hiyya advised his wife, “When a poor man comes to the door, be quick to give him food so that the same may be done to your children.” She exclaimed, “You are cursing our children [with the suggestion that they may become beggars].” But Rabbi Hiyya replied, “There is a wheel which revolves in this world.” —Babylonian Talmud, Shabbat 151b