https://thornhillkollel.com/wp-content/uploads/2016/03/eruvin-perek-beis-mishna-2-how-close-to-the-well-can-a-wall-be-built-in-order-to-draw-water-on-Shabbos.mp3“eruvin perek beis mishna 2 how close to the well can a wall be built in order to draw water on Shabbos”.