John Chrysostom
Catena Aurea · Matthäusevangelium 5
Think not that I am come to destroy the Law, or the Prophets: I am not come to destroy, but to fulfil. 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. 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.
Or, when you hear the words, least in the kingdom of heaven, imagine nothing less than the punishment of hell. For He oft uses the word ‘kingdom,’ not only of the joys of heaven, but of the time of the resurrection, and of the terrible coming of Christ.