"The choice first fruits of your soil you shall bring
to the house of the Lord your God.
You shall not boil a kid in its mother's milk." (Exodus 23:19)

This very enigmatic regulation appears in the context of laws regulating ritual and ceremonial aspects of the three pilgrimage festivals. Its importance may be measured by its being repeated twice more in the Torah, in Exodus 34:26 and Deuteronomy 14:21. In this latter source, the prohibition appears in the context of the dietary laws, but the other two sources indicate that its origin lies in the overall context of the festivals. The juxtaposition of this rule with the law of the first fruits led Menahem ibn Saruq (10th cent.) to interpret gedi not as a kid of the goats but as "berries."

This eccentric explanation was taken up by Menahem ben Solomon (early 12th cent.) who took "mother's milk" to be figurative for the juice of the bud that contains the berry. The entire passage conveyed to him a proscription on bringing the first fruits before they are ripe. Many medieval and modern scholars follow the suggestion of Maimonides (12th cent.) that this law prohibits some pagan rite – although no such rite is presently known.

Twelfth-century commentators Rashbam, Bekhor Shor and Ibn Ezra (12th cent.), and 15th-cent. commentator Abravanel all, in various ways, adduce a humanitarian motivation for not cooking a kid in its mother's milk. Rashbam further suggests that because festivals were celebrated with feasts of meat, and because goats are generally multiparous and have a high yield of milk, it was customary to slaughter one of the kids of a fresh litter and to cook it in its mother's milk. The Torah looks upon such a practice as exhibiting insensitivity to the animals' feelings.

The explanation of Rashbam has been buttressed by the modern observation that in biblical times, goats were far more plentiful than sheep in the Land of Israel and were the main source of milk; furthermore, the flesh of the young kid is more tender and more delicate in flavor than that of the lamb. Also, since the estrous cycle of goats occurs during the summer months and parturition takes place in the rainy season, the earliest litter would be produced just around the time of Sukkot. This injunction, therefore, regulates the festivities at the Festival of the Ingathering of the Harvest, ensuring that the killing of one of the kids of a fresh litter was not enacted as part of the ancient Israelite ritual.

The interdiction of boiling a kid in its mother's milk was generalized to outlaw the mixing of all meat and milk (meaning all dairy products). From its three-fold repetition in the Torah, the sages deduced a general prohibition against eating meat with milk, as well as its concomitant laws. (Kiddushin 57b).