Exodus 23:16, 19

and the Feast of Harvest, the firstfruits of your labors which you have sown in the field; and the Feast of Ingathering at the end of the year, when you have gathered in the fruit of your labors from the field.

The first of the firstfruits of your land you shall bring into the house of the LORD your God. You shall not boil a young goat in its mother’s milk.