“You shall not cook a kid in the milk of its mother.”
Exodus 23:19
Exodus 34:26
Deuteronomy 14:21
Judaism is filled with prohibitions, restrictions, laws of separation and sacrifice. Nowhere is this as clear as in the laws of kashrut.
“The prohibition of cooking meat and milk together applies to all sheep and cattle; not only kid meat in the milk of its own mother. The Torah gives this prohibition three times. It is forbidden to cook it, to eat it, and even to benefit from it. (Rashi). R’Hirsch suggests a reason for the prohibition and for its insertion in this passage. Meat represents the animal portion of life, the muscle and sinew. Milk represents the reproductive capacity of animal life, for milk is the nourishment that supports new life. In animals, these two aspects of life are inseparable; animals instinctively eat and reproduce. Man has a higher calling. He must not mingle these aspects of his nature. To the contrary, he must learn to differentiate between his activities and – primarily – to subjugate them all to this duty in the service of the God and to put Godliness into all his activities. The higher duty is symbolized in the prohibition against mixing milk and meat. Its proximity to the laws of the festivals and the first fruits conveys the teaching that one who succumbs to his animal instincts destroys the holy nature of the seasons and God’s blessings of prosperity.”
Etz Hayim