Nitai of Tekoa brought challah portions from Beitar, but [the Sages] did not accept [it] from him. People from Alexandria brought their challah [portions] from Alexandria, but [the Sages] did not accept [them] from them. People from Mount Tze-voim brought their bikkurim before [the festival of] Shavuos, but [the Sages] did not accept [them] from them, because of what is written in the Torah (Exodus 23:16): And the festival of the harvest, the first fruits of your labors, which you sow in the field.