The 613 commandments include "positive commandments", to perform an act (mitzvot aseh), and "negative commandments", to abstain from certain acts (mitzvot lo taaseh). The negative commandments number 365, which coincides with the number of days in the solar year, and the positive commandments number 248, a number ascribed to the number of bones and main organs in the human body.[2] Though the number 613 is mentioned in the Talmud, its real significance increased in later medieval rabbinic literature, including many works listing or arranged by the mitzvot. Three types of negative commandments fall under the self-sacrificial principle yehareg ve'al ya'avor, meaning "One should let oneself be killed rather than violate it".