What is the significance of the Minchah mentioned here?
Rashi: It is the Minchas Nesachim (a flour offering that accompanies an Olah or Shelamim) of the lamb.
Refer to 23:13:1:2.
The Sh'iur of flour for the Minchas Nesachim of the lamb that acompanies the Omer is two Esronim (double the regular Shi'ur for a lamb) and the Shi'ur of oil, the regular Revi'is ha'Hin. How much oil did it require?
Menachos, 89b: We learn from the fact that the word "Veniskoh Yayin Revi'is ha'Hin" is written with a 'Hey' (feminine with reference to the Minchah) but pronounced as if it was written with a 'Vav' (masculine with reference to Shemen) that the Shi'ur of the oil is a regular quarter Hin, like that of the wine
QUESTIONS ON RASHI
Rashi writes that the Minchah is Minchas Nesachim of the lamb. Minchas Nesachim of a lamb is only one Isaron!
Rashi: Here the Torah doubled the usual size of the Minchas Nesachim, even though the accompanying wine libation is the regular amount. 1
Da'as Zekenim, Hadar Zekenim: The simple meaning is, one Isaron is the Omer, and one Isaron is the regular Minchas Nesachim, just like the wine is the regular amount for a lamb. 2
Da'as Zekenim: Since we find a Minchas Nesachim larger than usual, in the Musafim (Bamidbar 28:9-29:15) the Torah specifies the Shi'ur of the Minchas Nesachim, but not the Shi'ur of the wine, since it is always the same. "ve'Nisko" is written with a 'Hey' (as if it is read 've'Niskah', feminine) to teach that it is the Nesech for the entire Minchah. Do not say that a quarter Hin is brought for each Isaron!
Seemingly, "Minchaso" implies that both Esronim are Minchas Nesachim! (PF)