“ אֵלֶּה תֹּלְדוֹת יַעֲקֹב, יוֹסֵף בֶּן-שְׁבַע-עֶשְׂרֵה שָׁנָה הָיָה רֹעֶה אֶת-אֶחָיו בַּצֹּאן,”
“These are the generations of Jacob. Joseph, being seventeen years old, was feeding the flock with his brethren ”
The Zohar explains that after Jacob established the connection to the Central Column, Zeir Anpin, he started to bring out ‘generations’. And those generations come from Joseph who is Yessod that brings the Light of Zeir Anpin to Malchut.
The analogy that the Zohar uses is of a unification of the Sun and the Moon to bring out ‘fruits’. The light of the sun (Zeir Anpin) is not revealed until it’s unified with the moon (vessel, Malchut). Only then, the light is revealed and the moon becomes visible and is the aspect of ‘fruit’. The Light itself is like river of water that comes from the levels of Chokmah and Binah. The river that comes out of this source ‘feeds’ the Sun with energy before Yessod continues the flow to Malchut.
Chokmah and Binah are the aspects of father and mother (right and left brain) that join together (knowing) to activate the flow of water through the middle brain (Da’at) through the spine to the system of Yessod, where these waters (seeds) are ‘cooked’ and shoot out into the vessel. This process brings fruits to the world.