The four teachings above are connected with the Four Worlds that the kabbalists saw as the architecture of the universe. When the Kabbalistic community of Tz’fat created the Seder for Tu BiShvat/ Yah BiShvat, they unfolded these Four Worlds in four cups of wine and four sorts of fruit and nuts (one sort so ethereal it was invisible and untouchable). This year, the full moon of Shvat will fall on Shabbat Shira itself, January 24-25.