Matthew 5:18
16 In the same way, let your light shine before people, so that they can see your good deeds and give honor to your Father in heaven. 17 “Do not think that I have come to abolish the law or the prophets. I have not come to abolish these things but to fulfill them. 18 I tell you the truth, until heaven and earth pass away not the smallest letter or stroke of a letter will pass from the law until everything takes place. 19 So anyone who breaks one of the least of these commands and teaches others to do so will be called least in the kingdom of heaven, but whoever obeys them and teaches others to do so will be called great in the kingdom of heaven. 20 For I tell you, unless your righteousness goes beyond that of the experts in the law and the Pharisees, you will never enter the kingdom of heaven!
Exodus Rabbah 6:1
AggadahAt that time, the letter yod went up on high and prostrated itself before God and said, 'Master of the Universe! Have you not said that no letter shall ever be abolished from the Torah? Behold, Solomon has now arisen and abolished one. Who knows? Today he has abolished one letter, tomorrow he will abolish another until the whole Torah will be nullified!' God replied, 'Solomon and a thousand like him will pass away, but the smallest tittle will not be erased from you.'
Notes and References
"... The law's intention was important, and debates about this (against its mere wording) could be important in forensic rhetoric. Gentiles would also understand Jesus' warning against removing even the tiniest part of the law (5:18), though Jesus' illustration is specifically Jewish. The repetition of 'shall be called in the kingdom of heaven' in two clauses of 5:19 would be viewed as antistrophe, or epiphora; while Matthew might not have used such a label, repetition was rhetorically effective in his milieu as well ..."
Keener, Craig S. The Gospel of Matthew: A Socio-Rhetorical Commentary (p. 178) William B. Eerdmans Publishing Company, 2009