Whosoever - shall break one of these least commandments - The Pharisees were remarkable for making a distinction between weightier and lighter matters in the law, and between what has been called, in a corrupt part of the Christian Church, mortal and venial sins. See on Matthew 22:36 (note).

Whosoever shall break. What an awful consideration is this! He who, by his mode of acting, speaking, or explaining the words of God, sets the holy precept aside, or explains away its force and meaning, shall be called least - shall have no place in the kingdom of Christ here, nor in the kingdom of glory above. That this is the meaning of these words is evident enough from the following verse.

shall break.

Deuteronomy 27:26 Cursed be he that confirms not all the words of this law to do them. And all the people shall say, Amen.

Psalm 119:6,128 Then shall I not be ashamed, when I have respect to all your commandments...

Galatians 3:10-13 For as many as are of the works of the law are under the curse: for it is written...

James 2:10,11 For whoever shall keep the whole law, and yet offend in one point, he is guilty of all...

these.

Matthew 23:23 Woe to you, scribes and Pharisees, hypocrites! for you pay tithe of mint and anise and cummin...

Deuteronomy 12:32 What thing soever I command you, observe to do it: you shall not add thereto, nor diminish from it.

Luke 11:42 But woe to you, Pharisees! for you tithe mint and rue and all manner of herbs, and pass over judgment and the love of God...

shall teach.

Matthew 15:3-6 But he answered and said to them, Why do you also transgress the commandment of God by your tradition...

Matthew 23:16-22 Woe to you, you blind guides, which say, Whoever shall swear by the temple, it is nothing...

Malachi 2:8,9 But you are departed out of the way; you have caused many to stumble at the law; you have corrupted the covenant of Levi...

Romans 3:8 And not rather, (as we be slanderously reported, and as some affirm that we say,) Let us do evil, that good may come?...

Romans 6:1,15 What shall we say then? Shall we continue in sin, that grace may abound...

1 Timothy 6:3,4 If any man teach otherwise, and consent not to wholesome words, even the words of our Lord Jesus Christ...

Revelation 2:14,15,20 But I have a few things against you, because you have there them that hold the doctrine of Balaam...

the least.

Matthew 11:11 Truly I say to you, Among them that are born of women there has not risen a greater than John the Baptist...

1 Samuel 2:30 Why the LORD God of Israel said, I said indeed that your house, and the house of your father, should walk before me for ever...

do.

Matthew 28:20 Teaching them to observe all things whatever I have commanded you: and, see, I am with you always, even to the end of the world. Amen.

Acts 1:1 The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach,

Romans 13:8-10 Owe no man any thing, but to love one another: for he that loves another has fulfilled the law...

Galatians 5:14-24 For all the law is fulfilled in one word, even in this; You shall love your neighbor as yourself...

Philippians 3:17,18 Brothers, be followers together of me, and mark them which walk so as you have us for an ensample...

Philippians 4:8,9 Finally, brothers, whatever things are true, whatever things are honest, whatever things are just, whatever things are pure...

1 Thessalonians 2:10-12 You are witnesses, and God also, how piously and justly and blamelessly we behaved ourselves among you that believe...

1 Thessalonians 4:1-7 Furthermore then we beseech you, brothers, and exhort you by the Lord Jesus...

1 Timothy 4:11,12 These things command and teach...

1 Timothy 6:11 But you, O man of God, flee these things; and follow after righteousness, godliness, faith, love, patience, meekness.

Titus 2:8-10 Sound speech, that cannot be condemned; that he that is of the contrary part may be ashamed, having no evil thing to say of you...

Titus 3:8 This is a faithful saying, and these things I will that you affirm constantly...

great.

Matthew 19:28 And Jesus said to them, Truly I say to you, That you which have followed me...

Matthew 20:26 But it shall not be so among you: but whoever will be great among you, let him be your minister;

Daniel 12:3 And they that be wise shall shine as the brightness of the firmament...

Luke 1:15 For he shall be great in the sight of the Lord, and shall drink neither wine nor strong drink...

Luke 9:48 And said to them, Whoever shall receive this child in my name receives me: and whoever shall receive me receives him that sent me...

Luke 22:24-26 And there was also a strife among them, which of them should be accounted the greatest...

1 Peter 5:4 And when the chief Shepherd shall appear, you shall receive a crown of glory that fades not away.

Salt Without Savour
'Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? It is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.'--MATT. v. 13. These words must have seemed ridiculously presumptuous when they were first spoken, and they have too often seemed mere mockery and irony in the ages since. A Galilean peasant, with a few of his rude countrymen who had gathered round him, stands up there on the mountain, and says to them, 'You, …
Alexander Maclaren—Expositions of Holy Scripture

The Lamp and the Bushel
'Ye are the light of the world. A city that is set on an hill cannot be hid. 15. Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house. 16. Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.'--Matt. v. 14-16. The conception of the office of Christ's disciples contained in these words is a still bolder one than that expressed by the preceding metaphor, which …
Alexander Maclaren—Expositions of Holy Scripture

The New Form of the Old Law
'Think not that I am come to destroy the law or the prophets: I am not come to destroy, but to fulfil. 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. 19. 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. 20. For I say …
Alexander Maclaren—Expositions of Holy Scripture