This discourse was taught by the Rebbe on Shabbat Mishpatim, Parshat Shekalim, in 1969. The extra reading speaks of giving half a shekel, which paid for two separate items: the silver sockets of the Sanctuary, and the public offerings. The sockets are the lowest part of the Sanctuary, on the ground; the offerings soar up to the Divine. The discourse explains that both these movements are needed in service of the Divine.