The point of Tu BiShvat is to make a connection between the “new year of the trees” and the core essence of the Jew.
This inner connection between man and tree is expressed in eating fruits; but it is also the connection between the Jews and the Land of Israel.
The entire cycle of the Jewish year is connected with the Land of Israel, as is reflected in the Jewish prayer book:
Almost every major prayer mentions the Land of Israel more than once.
But the prayer-book Land of Israel is an abstraction.
For many generations, and for so very many Jews, it was an imaginary entity, a dream land.
Even in the poetry of Rabbi Yehuda HaLevi the Land of Israel is not a reality: it is a spiritual being.
On Tu BiShvat we try to make contact with the physical, actual Land of Israel – the one that Rabbi Nachman of Braslav described after his visit there: that soil, the small stone houses, and the fruits that one can chew and taste their sweetness.
The Midrash describes how Moses pleads God to enter the Land of Israel.
Why did he want that so badly?
Some scholars say that it was because he wanted to fulfill the commandments that apply only in the Land of Israel.
But a literal reading of the text implies otherwise.
Moses, who wishes to see “that goodly hill-country and Lebanon” (Deut. 3:25), wants to enter the Land even as a small animal or bird – because it is “a pleasant land,” a land which, above and beyond all reckoning, is a sweet home.
On Tu BiShvat, when we eat the fruits of the Land of Israel, we celebrate the “pleasant” land aspect of the Land of Israel (see Zech. 7:14).
–Rabbi Adin Steinsaltz
From the essay “TuBishevat” by Rabbi Adin Steinsaltz