Reference for Menachot 10:6

הָעֹמֶר הָיָה מַתִּיר בַּמְּדִינָה, וּשְׁתֵּי הַלֶּחֶם בַּמִּקְדָּשׁ. אֵין מְבִיאִין מְנָחוֹת וּבִכּוּרִים וּמִנְחַת בְּהֵמָה קֹדֶם לָעֹמֶר. וְאִם הֵבִיא, פָּסוּל. קֹדֶם לִשְׁתֵּי הַלֶּחֶם, לֹא יָבִיא. וְאִם הֵבִיא, כָּשֵׁר:

The <i>omer</i> permitted [new grain] in the rest of the country and the two loaves [offered on Shavuot, permitted new grain] in the Temple. Grain offerings and first fruits [from the new produce] could not be brought before the <i>omer</i>, and if they were, they were invalid. They should not be brought before the two loaves, but if they were they are still valid.

Jastrow