The word bikurim was popularized in the Messianic movement in the wake of, “Yom haBikurim,” the day ‘after Shabbat’
In verse 20, the lechem haBikurim, or “bread of the first fruits,” is mentioned and in Numbers 28:26 the Feast of Shavuot is called Yom haBikurim. Have we learned something wrong again? Not quite. The reality is, thematically speaking, that the “beginning of the harvest,” those fruits of the barley harvest offered during the week of Chag haMatzot (Feast of Unleavened Bread), from when we began to count the fifty days until Shavuot may also be called bikurim. So, if we want to define the terms correctly and accurately, it is important to understand that the Day of First Fruits is NOT called ‘Yom haBikurim’ in the Torah. On the contrary, the day that is called ‘Yom haBikurim’ is Shavuot, as we saw above. Finally, I will share the meaning of this word. Bikurim is the plural of the word bikur, which is literally “first,” related to organic elements such as animals, fruits and plants. It is related to the root bakr which means “firstborn.” In Egypt, for example, the tenth plague was called makat haBechorot, “plague of the firstborn.” As expressed biblically, the first “fruit of the womb” of a woman is linguistically related to the first fruits of the earth.
Bring from your dwellings for a wave offering two loaves of bread, of two-tenths of an ephah of fine flour they are, baked with leaven, first-fruits (bikurim) to YeHoVaH. – Leviticus 23:17