Reference for Rosh Hashanah 25:15

א"ר זירא הא מילתא הואי בידן ואתא רבי חנינא שדא ביה נרגא

But perhaps [the Israelites brought the omer from] corn which had not commenced to grow [when they entered the land], but where it had grown to a quarter they were not certain about the difference between a third and less than a third?<span class="x" onmousemove="('comment',' And it was not from such corn that they brought the omer.');">¹²</span> - Do not imagine such a thing.

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