The Zohar tells us that בראשית is Israel ישראל with the same letters as לי ראש, “head for me”. “Head” implies to Zeir Anpin that is called Israel on the supernal levels of Father and Mother (Chokmah and Binah).
In Jeremiah 2:3 we read
“קדש ישראל ליהוה ראשית תבואתה” , “Israel is God’s hallowed portion, the first of the crops (fruit)…”.
The first of the crops means that it comes without being mixed with negativity. It is only Chassadim, meaning without any kind of judgment.
All that is Holy connect to the ‘Head’ and becomes a channel for the supernal light. It needs to be protected from negative influence when it revealed in the Malchut level.