A.T. Robertson Commentary Matthew 5:18

"For verily I say unto you, Till heaven and earth pass away, one jot or one tittle shall in no wise pass away from the law, till all things be accomplished." — Matthew 5:18 (ASV)

One jot or one tittle (ιωτα εν η μια κερεα). "Not an iota, not a comma" (Moffatt), "not the smallest letter, not a particle" (Weymouth). The iota is the smallest Greek vowel, which Matthew here uses to represent the Hebrew yod (jot), the smallest Hebrew letter. "Tittle" is from the Latin titulus which came to mean the stroke above an abbreviated word, then any small mark. It is not certain here whether κερεα means a little horn, the mere point which distinguishes some Hebrew letters from others or the "hook" letter Vav. Sometimes yod and vav were hardly distinguishable. "In Vay. R. 19 the guilt of altering one of them is pronounced so great that if it were done the world would be destroyed" (McNeile).