Word Study: jot (Greek word iōta - we get the english word "iota")
The Hebrew letter `, the smallest of them all. Equivalent to the extremely smallest part.
Word Study: tittle (Greek word keraia) something horn-like, i.e. (specially) the apex (the top or highest part of something, especially one forming a point) of a Hebrew letter (figuratively, the least particle)
Mat 5:18
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.