In Judaism, Lifnei Iver (Hebrew: לִפְנֵי עִוֵּר, romanized: lifnê ʿiwwēr, "Before the Blind") is a Hebrew expression defining a prohibition against misleading people by use of a "stumbling block," or allowing a person to proceed unawares in unsuspecting danger or culpability. The origin comes from the commandment וְלִפְנֵ֣י עִוֵּ֔ר לֹ֥א תִתֵּ֖ן מִכְשֹׁ֑ל וְיָרֵ֥אתָ מֵּאֱלֹהֶ֖יךָ "Before the blind, do not put a stumbling block" (Leviticus 19:14).
The Hebrew term lifnei iver is one of the offenses which the Talmud argues to be punishable by excommunication in Judaism.
The stumbling block as a distinct, and negative, concept is also established in Christian theology: in the Catholic Church, it is known as creating scandal.