Numbers 28:24-26

New Revised Standard Version Catholic Edition

²⁴ In the same way you shall offer daily, for seven days, the food of an offering by fire, a pleasing odor to the Lord; it shall be offered in addition to the regular burnt offering and its drink offering. ²⁵ And on the seventh day you shall have a holy convocation; you shall not work at your occupations.

Offerings at the Festival of Weeks

²⁶ On the day of the first fruits, when you offer a grain offering of new grain to the Lord at your festival of weeks, you shall have a holy convocation; you shall not work at your occupations.