Exodus 23:19
Exodus 23:19
The biblical prohibition 'You shall not boil a kid in its mother's milk' appears three times in the Torah and is the ultimate source from which the rabbis derive the separation of meat and dairy, including the waiting period.
רֵאשִׁ֗ית בִּכּוּרֵי֙ אַדְמָ֣תְךָ֔ תָּבִ֕יא בֵּ֖ית יְהֹוָ֣ה אֱלֹהֶ֑יךָ לֹֽא־תְבַשֵּׁ֥ל גְּדִ֖י בַּחֲלֵ֥ב אִמּֽוֹ׃ {פ}
The choice first fruits of your soil you shall bring to the house of the ETERNAL your God. You shall not boil a kid in its mother’s milk.