The lactose intolerant among us should probably look away now. 

For generations, Shavuot has been traditionally celebrated by eating milk and cheese products, with cheesecake, blintzes and other such dairy delights taking centre stage at kiddushim. Yet the reason behind this fascinating (albeit less than healthy) custom is somewhat shrouded in mystery.

The earliest written source appears to be in the 15th-century work, Sefer Haminhagim, “The Book of Customs”, by the Hungarian rabbi, Yitzchak Tyrnau. He implies that the custom was already well- established at that time and offers an opinion for the reason, noting that the phrase “a new meal offering to the Lord, on your festival of Shavuot, minchah chadashah l’Adonai b’Shavuoteichem (Numbers 28:26) contains the acronym chalav, the Hebrew for milk.

While this might seem a stretch, perhaps the most familiar explanation is that of Rabbi Yisrael Meir Hakohen Kagen known as the Chofetz Chaim (who died in 1933). Shavuot commemorates God giving the Torah to Moses and the Jewish people on Mount Sinai just over 3,300 years ago. 

The Chofetz Chaim notes that since the laws of kashrut were not known beforehand, when the Jewish people returned to their homes following the revelation at Sinai, they were unable to eat meat. Doing so would now require shechita, the removal of the sciatic nerve and the forbidden fats (porging) and preparation through the removal of blood through salting. Their cooking utensils would also have to be kashered (purged), having previously been used for non-kosher food. Consequently, until these requirements were met only dairy foods could be eaten.

One might ask why the Jewish people couldn’t have just slaughtered animals there and then, kashered their pots and pans and cooked new kosher meat meals to celebrate Shavuot. According to the Gemara, the Torah was given on Shabbat and so it would have been prohibited to slaughter animals, kasher pots and cook food as these are classed as melachah, creative activities which are prohibited on the Sabbath (Shabbat 87a). Consequently, our ancestors ate milk and dairy products instead.

Although the Chofetz Chaim’s explanation provides historical context to the tradition of eating dairy on Shavuot, rabbinic minds have long recognised the deeper meanings behind our sacred customs. 

The Jewish mystical tradition relates milk and meat to the two the metaphysical concepts of chesed (loving-kindness) and din (judgement). The link between the two concepts can be explained in the following way. Milk is produced by a mother and given freely to nourish her child. The production of milk is a pure act of chesed on the mother’s part, while the child is completely dependent on the supply of milk for its survival.

Meat on the other hand must be produced by the slaughter of an animal. Its death represents the ultimate judgement which corresponds to din.

Many kabbalistic sources, including Rabbi Yaakov Tzvi Yalish in his book Kehillas Yaakov, explain that the reason we may not mix meat and milk is together is that the admixture of chesed and din would be spiritually damaging to us.

The Gemara expands on the analogy by citing a verse in Proverbs (5:19), which compares the study of Torah to a suckling child (Eruvin 54b). As soon as the child is able to suckle, its mother produces milk. Yet when the child stops nursing, the milk dries up. The Gemara explains that when someone engages in learning Torah, they will always be inspired and find sources of spiritual sustenance. When their engagement with learning Torah stops, the source of their spiritual nourishment dries up too. However much they practise Jewish law or perform mitzvot, God’s commandments, they will always be lacking if they don’t engage in learning Torah.

If we continue the analogy further, it is interesting to note that milk is produced by small sacs in the mammary glands called alveoli, which extract proteins, sugars and fat from the mother’s blood. The levels of these nutrients are controlled to provide the most appropriate mixture at each stage of the baby’s development. The initial milk (colostrum) is high in protein and low in fat so that is easily digested by the new born. But as the baby grows, the fat content increases to help the baby gain weight.

The analogy highlights perhaps the most beautiful aspect of learning Torah. The same Torah which teaches and nourishes the minds of young children is also studied by the greatest scholars and rabbis. From beginner to expert, the study of Torah always has the power to inspire and stimulate a connection to the Divine. The lesson of milk on Shavuot enlightens us to the greatest act of chesed, which God bestowed on his people: the potential for growth by means of the most inclusive and yet comprehensive didactic system ever.

Dr Freedman is rabbi of New West End Synagogue