jot and tittle

A reference to Matthew 5:18 in the Bible (King James Version; spelling modernized): “For verily I say unto you, till heaven and earth pass, one jot or one tittle, shall in no wise pass from the law, till all be fulfilled.” The Koine Greek phrase is ἰῶτα ἓν ἢ μία κεραία (iôta hèn ḕ mía keraía). Jot (“the smallest letter or stroke of any writing, iota”) is derived from Middle English jote (“jot, tittle, whit”), from Latin iōta (“the Greek letter iota (Ι, ι)”), from Ancient Greek ἰῶτα (iôta, “the letter Ι, ι, the smallest in the alphabet; (figurative) a very small part of writing, jot”), from Phoenician 𐤉 (y‬ /yōd/). Tittle (“small dot, stroke, or diacritical mark; (figurative) small, insignificant amount, modicum, speck”) is derived from Middle English title (“small written mark or stroke; smallest part”) [and other forms], from Anglo-Norman title, tittle [and other forms], and Middle French titele, title (“inscription”) (modern French titre), and from their etymon Latin titulus (“epitaph, inscription”); further etymology uncertain, but thought to be of Etruscan origin.

来源：wiktionary