Ecclesiastes Rabbah 12:4

¹“The doors to the street will be shut, with the fading of the sound of the mill; and one will arise to the voice of a bird, and all the sources of music will be lowered” (Ecclesiastes 12:4). “The doors to the street will be shut” – these are a person’s orifices; “with the fading of the sound of the mill” – because the stomach is not grinding; “and one will arise to the voice of a bird” – the elderly, when they hear the birds tweeting, they say: Robbers are coming to rob me; “and all the sources of music will be lowered” – these are the lips. Rabbi Ḥiyya ben Rabbi Neḥemya says: These are the kidneys that conceive, and the heart concludes.