Dear Rabbi, I was wondering if you could explain why in Judaism we give precedence to the right side over the left side. For example, when washing hands we wash the right side before the left?

The Book of Job (Eyov 19, 26) teaches “from my body, I can see God”, that the physical world, and especially the body of man (the goal of creation), can teach us about the meta-physical/spiritual world of our Creator. The ten sfirot which the kabbalah uses to explain the body/world/and, as if it were, G-d, attributes the right hand, which we use for giving, as the symbol of chesed (kindness), and the left hand, important but secondary, used to balance that kindness with gvura (strength). The delicate balance is truly challenging, but it must be clear that altruistic chesed is a little more primary than gvura. Accordingly, most religious actions in Judaism are symbolically done with a preference for the right-hand, like when both Ya’akov and Yosef saw the preferential bracha through its use (Breishit 48, 13-20). Additionally, the stronger hand symbolizes energy and zeal, so we demonstrate our enthusiasm to do mitzvot by doing them with our strong-hand which is usually the right (although when this reason applies, “lefties” will do the left-hand first). Thus, we hold the Kiddush cup with our stronger hand, which again, by most people shows preference to the right.