The Body in Old Age as Solomon's Riddle in Tanchuma

(Continuing:) "And those who look <through the windows> grow dim" (Ecclesiastes 12:3) — these are the eyes. "And the doors to the street are shut" (Ecclesiastes 12:4) — these are the legs. Why? When a person grows old, he does not multiply his steps in the street, for his legs are gathered in from the street. "When the sound of the grinding is low" (ibid.) — because he has become sluggish over eating. "And he rises at the sound of the bird" (ibid.) — Rabbi Levi bar Rabbi Shalom said: Even when he hears the sound of a bird chirping, he supposes that perhaps they are robbers.