The Hebrew zur means to be a stranger, to be foreign, to turn aside. The participle zar ('strange one') describes anyone outside the covenant community — a foreigner, an outsider, or one who is 'other'. It can also describe unauthorized approach to the holy (i.e., one who is 'strange' to the sacred office).
The concept of the zar (stranger) runs throughout the Mosaic law and Wisdom literature with rich theological layers. At the social level, Israel was commanded to remember they were once strangers (gerim) in Egypt and to treat foreigners with justice (Deuteronomy 10:19). At the cultic level, zar denoted anyone not of the priestly line who approached the altar — an act of unauthorized presumption punishable by death (Numbers 18:7). In Proverbs, zarah ('strange woman') is the personification of Folly and adultery — the seductress who lures men away from wisdom and covenant. Spiritually, the imagery of 'stranger' reminds Israel (and us) that belonging to God's household is a gift of grace, not a right of birth.