AyinBase with R' Paltiel Wednesday 25 Kislev 5772
Page 63 at the middle of the final paragraph of the page (line starts, 'bezun').
See link (top right) for link to all pages of the text.
We are looking at the meaning of Israel requesting the 'kisses of his mouth'.
It would seem that the yichud zun is more profound than the union of kisses. So why the request? We explained that there is a certain way that kisses are superior.
Although kisses are on the level of 'reflection' and not essence, but still this is a reflection of a higer level and it is thus higher than the essence of the lower level.
The Rebbe explained that the bodily union is essential and has a greater level. He says 'greater' not 'higher'. He means it is more essential but not of a higher level.
Yichud chitzoni/external is seen in rav/teacher and student. The teacher gives of his essence, but there is a 'platform' of the union. There is an intermediary level that connects them – the mind and the words.
Yichud pnimi is seen in father and son. There is no intermediary. It is essence to essence.
Yichud zun is a marriage. Two individuals are involved. How does the union occur. In Torah this is a true union, not based on physical desire. What unites them? The shchinah dwells in the home and in their union and it is the shchina that unites them. It represents the essence of elokus/G-dliness and through this is revealed an element of eternity. The reason that sphirot are unified with malchus is because through this they both connect to kesser/crown which is above the whole creative process.