In Ex 23:19, Ex 34:26, and Deut 14:21-22, the Bible gives the command “You shall not boil a young goat in its mother’s milk.” Some say this expression means we can’t eat cheese and meat together or cheeseburgers, others say it’s a Canaanite ritual but actual archeological evidence backing that up is nonexistent. I’ve only seen speculative internet articles, none of which don’t reference actual Canaanite writings. Also, all the commands related to Canaanite practices are in the moral laws section of Leviticus (Lev 18-20). Some say it’s about respecting nature, but if that’s the case wouldn’t it have said this for all animals, not just goats? There is a theory that this is an ancient idiom that lost its meaning over time, and I think this is the most likely case, based on the evidence. There are three places where this sentence is mentioned in the Bible, all three times it is surrounded by the same context of tithes and offerings.
Both verses in Exodus say the same thing: “As you harvest your crops, bring the very best of the first harvest to the house of the Lord your God. You must not cook a young goat in its mother’s milk.” (NLT) (Ex 23:19, Ex 34:26)
Deut 14:21-22 (NLT) “ 21 You must not eat anything that has died a natural death. You may give it to a foreigner living in your town, or you may sell it to a stranger. But do not eat it yourselves, for you are set apart as holy to the Lord your God. You must not cook a young goat in its mother’s milk. 22 You must set aside a tithe of your crops—one-tenth of all the crops you harvest each year.
In the Exodus passages, it appears directly following a mention of first fruit offerings meanwhile the Deuteronomy passage appears before the yearly tithe command. God commands Israel to bring good sacrifices, as in the best and the first of their harvest. However, in their hard-heartedness and lack of trust, some would take some of last year’s leftover yield, from the bottom of the barrel and mix it in with the new wheat. The idea is that the mother’s milk represents a previous generation and the newborn young goat is the first fruit of the current year. This figure of speech could mean do not combine the old with the new, or one generation of crops with the next. This is similar to Jesus’s idiom of not pouring new wine into old wineskins when referring to blending the old and new covenant (Matt 9:17, Mark 2:22, Luke 5:37). This makes more sense in the context of sacrificing since all three verses are surrounded by verses about tithes and offering.
This article introduced me to the idea:
https://www.southernplate.com/do-not-boil-a-young-goat-in-its-mothers-milk-another-possibility/