Matthew Poole on Matthew 5:18-19
The following is from Matthew Poole's commentary, edited and modernized.
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.
Matthew 5:18
Till heaven and earth pass, etc. That is, the law is the certain and unchangeable will of God concerning reasonable creatures, and it shall never be altered in the least tittle, nor ever be abolished; you may therefore be secure that I come into the world upon no such errand.
Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.
Matthew 5:19
Whosoever shall in his practice violate but one of the commandments of God, which the Pharisees judge of the least, and which possible are so compared with others, and shall teach men that they may do likewise, making such false interpretations of the law as may warrant such a practice, he shall be accounted of the least value and esteem in the church of God, and shall never come into the kingdom of glory. But he who shall strictly and uniformly obey all the commandments, and teach others to do likewise by his doctrine and example, that man shall have a great renown and reputation in the church, which is the kingdom of heaven upon earth, and shall have a great reward in the kingdom of glory hereafter.