(Beraisa - R. Yehudah): In this world, grain grows in six months, and a tree produces [fruits] after 12 months, but in the future, grain will grow in one month, and a tree will produce after two months. What is the source? "La'Chadashav Yevaker.''

R. Yosi says, in this world, grain grows in six months, and a tree produces after 12 months, but in the future, grain will grow in 15 days, and a tree will produce after one month;

Source: We find that grain grew in the days of Yo'el in 15 days, and they offered the Omer from it. (After seven years of famine, people planted their last seeds on Rosh Chodesh Nisan, and it grew in 15 days.)

What is the source of this? "U'Vnei Tziyon Gilu v'Simchu ba'Shem Elokeichem Ki Nasan Lachem Es ha'Moreh li'Tzedakah va'Yored Lachem Geshem Moreh u'Malkosh ba'Rishon.''

Question: How does R. Yosi establish the [verse] from which R. Yehudah learned?

Answer: "La'Chadashav Yevaker'' - every month it will bring Bikurim (new fruits).