וארבעים אדני כסף תעשה…(תרומה כו:יט)

The foundation of Yiddishkeit is אהבת השם – to love Hashem.  All mitzvos we perform have one goal: with every mitzvah that one does out of love, a person comes closer to Hashem.  This is alluded to in the word כסף – silver, which can be translated as longing (as we say in the third stanza of the song Yedid Nefesh: נכסוף נכספתי). The sockets were made of silver, alluding to the fundamentals of Yiddishkeit: אהבת השם.