Halakhah for Menachot 151:9

The commandment of the sacrifice of the new meal-offering from wheat on the day of [Shavuot]: To sacrifice leavened bread from the new wheat on the day of the festival of Shavuot. And that is what is called in Scripture, "a new offering" (Leviticus 23:15). And they are two loaves, as it is written (Leviticus 23:16), "From your inhabitations you shall bring bread of waving, two of two issaron." And the matter was such that they would bring three seah of new wheat and rub them and pound them in the way of all of the meal-offerings. And they would grind them and sift two issaron in twelve sieves. And they would take them and make two loaves from them and bring leavening (Menachot 52b) and put it into the issaron. And the length of each loaf was three handbreadths and its width was four, and its height was [the span of] four fingers (Menachot 96a). And they were square; and they were baked on the eve of the holiday. And on the morrow after their waving, they were eaten by the priests that whole day and half the night (Menachot 100b). And that meal-offering is the first of all of the meal-offerings [of that crop] of wheat. And with the bread, they would sacrifice seven unblemished sheep, one young bull and two rams for a burnt-offering, a goat for a sin-offering and two lambs for a peace-offering - and these are the sacrifices spoken about in [the Book of Numbers]. All of this was brought with the bread besides the additional offering of the day which was two bulls, one ram and seven lambs for a burnt offering, and one goat for a sin-offering - and these are the sacrifices spoken about in the Book of Leviticus. And it was elucidated explicitly so in the fourth chapter of Menachot 45b that this sacrifice would come with the bread, separate from the additional sacrifice of the day. And after the waving of the bread, it was eaten by the priests with the lambs of the peace-offerings.