Kephas is the Aramaic equivalent of the Greek Petros ('rock'), the name Jesus bestowed on Simon (John 1:42). What makes this form distinctive is its distribution: while the Gospels overwhelmingly use 'Peter,' Paul almost exclusively uses 'Cephas' in his letters (1 Cor 1:12; 3:22; 9:5; 15:5; Gal 1:18; 2:9,11,14). This preference likely reflects Paul's direct contact with the Aramaic-speaking Jerusalem church, where the apostle was known by his Semitic name. The Aramaic kepha ('rock, stone') is preserved intact through Greek transliteration, reminding readers that the church's foundational apostle bore a name rooted in Jesus's own mother tongue. Only John 1:42 explains the name's meaning for Greek readers, translating it as Petros.