[kr2]

This is still used today by Jews for Hebrew names. "Bar", the Aramaic word for "son", has in Hebrew its counterpart "ben" ("bat" for women). So your Hebrew name is eg "David ben Benjamin", David son of Benjamin. This is used anywhere to address you in Hebrew, eg for bar/bat mitzvahs, calling up to give blessings in synagogue, headstones, on your ketubah (Jewish marriage license), etc