For verily I say unto you, Till heaven and earth pass away, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
All Commentaries on Matthew 5:18 Go To Matthew 5
Augustine of Hippo
AD 430
For, if even those things which are added for completion are fulfilled, much more are those things fulfilled which are sent in advance as a commencement. Then, as to what He says, One iota or one tittle shall in nowise pass from the law, nothing else can be understood but a strong expression of perfection, since it is pointed out by means of single letters, among which letters iota is smaller than the others, for it is made by a single stroke; while a tittle is but a particle of some sort at the top of even that. And by these words He shows that in the law all the smallest particulars even are to be carried into effect.
