The miracles of modern science have made us aware of the vast world of micro-organisms that previous generations never knew existed. We now know that there are good bacteria that help us digest food and bad bacteria that make people ill. Viruses abound, ranging from those that cause a slight cold to those that bring on a flu that leaves us bed-ridden. All this is unseen by the naked eye.

Just as we rely on scientists and doctors to understand and explain how these micro-organisms interact with our environment, Jews rely on specialists (sages) to understand the unseen forces of the spiritual world.

For instance, the sages instruct us that before we eat a piece of food on which there is liquid, one’s hands must by ritually washed (like the washing before bread). The Kitzur Shulchan Aruch (Abridged Code of Jewish Law) states: “If one eats some food which has been dipped in a liquid, or if a liquid has been poured on the food, even though one does not touch that part of the food where the liquid is, yet one must wash the hands first” without reciting a blessing. In the Talmud (Pesachim 115a), the sages discuss this law in relation to the idea that liquid on food becomes a conductor of spiritual impurities from the hand to the food.

Today, most consumers are careful to wash fruit and vegetables to rid them of any remaining pesticide residue. These chemicals are invisible to the naked eye, and yet we recognize that their dangerous residue often remains on the fruit. So too, the spiritual impurities on wet fruit are invisible to the naked eye. Since the experts (rabbis) tell us that they are dangerous, we dry the produce after washing it, as this is important for our spiritual well-being.