Commentary for Numbers 28:26

וביום הבכורים AND ON THE DAY OF THE FIRSTLINGS — The Feast of Weeks is called the firstlings of the wheat harvest (Exodus 34:22) because of the two loaves (Leviticus 23:17) which were the first of the wheat meal offerings which were brought from the new grain (Menachot 84b).

בשבועותיכם, on account of the weeks of cutting, harvesting. Compare Jeremiah 5,24 שבועות חקת קציר, “the weeks appointed for the harvest.” The reason for the apparently superfluous letter ב at the beginning of this word here is similar to the use by Scripture of the same letter in constructions such as בנפש יכפר in Leviticus 17,11, or בדם עשהאל in Samuel II 3,27, or בלחם נשכרו in Samuel I 2,5. It is a form of emphasis of the word it introduces.

בהקריבכם…בשבעתיכם, when you offer on your festival of weeks, etc. The plural indicates that this festival is not only meant for bringing the offering from the new wheat harvest, but that at the same time it also symbolises the completion of the count of the seven weeks commencing with the second day of Passover. This represents a major rehabilitation of our souls as explained by the Kabbalists. The Torah is careful to use the possessive suffix to indicate that the seven weeks represent the essential elements which distinguished the seven righteous people who between them form the spiritual foundation of the Jewish people. This is explained in detail in Tikkuney Hazohar chapter 21.