The tenth letter of the Hebrew alphabet. It is the smallest of the Hebrew letters. The name of the smallest letter of the Greek alphabet, i·oʹta, evidently is akin to the Hebrew yohdh. Since the Law of Moses was originally written and subsequently preserved in Hebrew, it is likely that Jesus was referring back to the Hebrew yohdh when he said that the “smallest letter [Gr., i·oʹta]” would not pass away without its due fulfillment. (Mt 5:18) This letter occurs as the initial letter in the Tetragrammaton, or sacred name Jehovah (reading from right to left: יהוה), and as such was carried over into the earliest copies of the Greek Septuagint. A vellum leaf of the third century C.E. (P. Oxyrhynchus vii. 1007) containing a portion of the Septuagint translation of Genesis represented the divine name Jehovah by a doubled yohdh.
Because of the similarity between the letters yohdh (י) and waw (ו), they were sometimes confused by copyists. In the Hebrew, at Psalm 119:73-80 each verse begins with the letter yohdh.