The Torah stresses the word tzelem (image) in its description of how man was created in "a divine image" (Bereishit 1:26-27). It also seems to connect this distinction to the fact that man was created as male and female. According to all explanations, the concept of "in the image of Hashem" relates mainly to man’s spiritual side; this is not related to man’s physical side, which is actually connected to sinning. In the second description of man’s creation (ibid. 2:7), the Torah does describe a physical creation ("earth from the ground"), into whom Hashem breathed, thereby providing him with a living spirit.
In the description of the creation of the first woman (ibid. 21-23), a prominently repeated word is tzela. This word shares the first two Hebrew letters with tzelem, and in both cases, the connection between man and woman is in the forefront. Let us try to understand the significance of the tzela to this element of creation. According to the standard opinion in Chazal (Bereishit Rabba 80) and among commentaries such as the Ramban, the tzela is the bone (rib) from Adam’s body from which she was created. Another opinion connects the word to the one for the "side wall" of the Mishkan. Accordingly, Adam and Eve were created back-to-back as full forms, who were separated from each other’s side. The varied opinions can be said to symbolize different outlooks as to the relative prominence of man and woman.
Let us now connect tzela to a third and related concept – a physical phenomenon with great spiritual implications – tzel (a shadow). The Rama (Orach Chayim 664:1) cites the belief that there is a hint in the shadow of the moon on Hoshana Rabba as to what will happen to a person and his relatives during the course of the year. The Rama, though, prefers the opinion that one should not seek to see that hint: because it can be a bad omen, because few people can decipher it, and because it is better to be tamim (unquestioning) rather than try to predict the future.
We can suggest, then, that tzel represents the connection with Hashem. This certainly finds expression with the aforementioned tzelem. It continues with the life-giving force that accompanied the taking of the tzela from Adam. The removal of one’s tzel is a sign of their disconnection from its life source (see Bamidbar 14:9). We can now more greatly appreciate the statement of Chazal that when husband and wife are interacting properly, the Divine Presence is among them (Sota 17a). The tzela represents a person’s ability to strive for spiritual greatness and cling to the Divine Presence despite his having come from earth. His connection to his/her spouse is a secret recipe for success.
Returning to the sukka, its shade also represents the closeness to Hashem, and a sukka must have mainly shade to be kosher. The word hatzala (salvation) is also related. We receive salvation when Hashem protects us.
May we merit having personal and national connection to Hashem, and, in the merit of the tzela, may we maximize the tzelem and have hatzala.