18 is considered "chai" because of its connection to the Hebrew word for "life."
Here's a breakdown:
- The Hebrew word for "life" is "chai" (חי).
- In Hebrew, letters also represent numbers.
- The letter Chet (ח) has a numerical value of 8.
- The letter Yud (י) has a numerical value of 10.
- Therefore, "chai" (חי) equals 8 + 10 = 18.
So, 18 stands for "chai" or "life." This is why giving gifts or donations in multiples of 18 is a common practice in Jewish culture, symbolizing a blessing for life. The custom of giving charity in multiples of 18 is relatively recent compared to other Jewish customs. One possible origin of this practice is from the Kaparot ritual performed on the day before Yom Kippur.
