What episode is Beth's joke, Jiang Ke?

The bladder meridian of Foot Taiyang occupies a very important position in human meridians, and its main function is to control water, that is, to regulate water-liquid metabolism. The bladder meridian of foot sun is also closely related to the activities of limbs. At the ends of limbs, that is, fingers and toes of hands and feet, there are several acupoints related to bladder meridian of foot sun. By stimulating these acupoints, the blood circulation of limbs can be promoted and the activity ability of limbs can be enhanced.