T6 (Tinyana) PNC - Al Yedei Ze'ah Tovah Na'asis Simchah (Through Good Sweat, Joy is Made)

Through good sweat — the sweat one produces while exerting oneself in matters of holiness — joy is made. This is the aspect of 'And you shall rejoice in your festival' (Devarim 16:14), the joy of yom tov, which is not the trivial joy of leisure but the joy that emerges from labor turned holy. The body that has sweated for HaShem becomes the body that can hold festival joy.

And this is what we see clearly: the sick person, immediately when he begins to sweat, joy is drawn upon him. The body's healing is signaled by sweat; the soul's healing carries the same sign. Holy sweat — sweat from labor in mitzvos, in tefillah, in study — itself draws down simchah, just as fever-sweat draws down the breaking of illness. The mechanism is one in body and soul.