Mischna zu Schemot 23:16

Bikkurim are brought only from the seven species. Not from dates grown on hills, nor from [the other species] grown in the valley, nor from olives that are not choice. Bikkurim are not to be brought before Shavuot. The people from Mt. Zevoim brought bikkurim prior to Atzeret (Shavuot), but they did not accept from them, on for it is written in the Torah: “And the festival of the harvest, the first-fruits of your labors, which you have sown in the field” (Exodus 23:16).

Nittai of Tekoa brought hallah-portions from Be-Yitur, but they did not accept from him. The people of Alexandria brought hallah, but they did not accept from them. The people from Mt. Zevoim brought bikkurim prior to Atzeret (Shavuot), but they did not accept from them, on for it is written in the Torah: “And the festival of the harvest, the first-fruits of your labors, which you have sown in the field” (Exodus 23:16).