Wherefore ye be witnesses unto yourselves, that ye are the children of them which killed the prophets.

People's New Testament

23:31 Wherefore ye be witnesses, etc. They demonstrated by their hostility to Christ, by their plots and false charges, and would soon show by their murder of the Lord, that they had just the same spirit as their fathers who slew Isaiah, persecuted Jeremiah, and shed the blood of Zacharias between the altar and the temple. They were therefore their spiritual children as well as their descendants. It adds to the vividness of this denunciation that from the temple area where they were standing the crest of Olivet rose distinctly at the distance of half a mile, and upon it were clearly visible the white sepulchers of the prophets which they had built, among them the tomb of Zacharias, who is named just below as slain between the temple and the altar (Mt 23:35).

Wesley's Notes

23:31 Wherefore ye testify against yourselves - By your smooth words as well as devilish actions: that ye are the genuine sons of them who killed the prophets of their own times, while they professed the utmost veneration for those of past ages. From the 3d to the 30th verse Mt 23:3 - 30 is exposed every thing that commonly passes in the world for religion, whereby the pretenders to it keep both themselves and others from entering into the kingdom of God; from attaining, or even seeking after those tempers, in which alone true Christianity consists. As, Punctuality in attending on public and private prayer, ver. 4 - 14. Mt 23:4 - 14 Zeal to make proselytes to our opinion or communion, though they have less of the spirit of religion than before, ver. 15. Mt 23:15 A superstitious reverence for consecrated places or things, without any for Him to whom they are consecrated, ver. 16 - 22. Mt 23:16 - 22 A scrupulous exactness in little observances, though with the neglect of justice, mercy, and faith, ver. 23, 24. Mt 23:23,24 A nice cautiousness to cleanse the outward behaviour, but without any regard to inward purity, ver. 25, 26. Mt 23:25,26 A specious face of virtue and piety, covering the deepest hypocrisy and villany, ver. 27, 28. Mt 23:27,28 A professed veneration for all good men, except those among whom they live.

Matthew Henry's Concise Commentary

23:13-33 The scribes and Pharisees were enemies to the gospel of Christ, and therefore to the salvation of the souls of men. It is bad to keep away from Christ ourselves, but worse also to keep others from him. Yet it is no new thing for the show and form of godliness to be made a cloak to the greatest enormities. But dissembled piety will be reckoned double iniquity. They were very busy to turn souls to be of their party. Not for the glory of God and the good of souls, but that they might have the credit and advantage of making converts. Gain being their godliness, by a thousand devices they made religion give way to their worldly interests. They were very strict and precise in smaller matters of the law, but careless and loose in weightier matters. It is not the scrupling a little sin that Christ here reproves; if it be a sin, though but a gnat, it must be strained out; but the doing that, and then swallowing a camel, or, committing a greater sin. While they would seem to be godly, they were neither sober nor righteous. We are really, what we are inwardly. Outward motives may keep the outside clean, while the inside is filthy; but if the heart and spirit be made new, there will be newness of life; here we must begin with ourselves. The righteousness of the scribes and Pharisees was like the ornaments of a grave, or dressing up a dead body, only for show. The deceitfulness of sinners' hearts appears in that they go down the streams of the sins of their own day, while they fancy that they should have opposed the sins of former days. We sometimes think, if we had lived when Christ was upon earth, that we should not have despised and rejected him, as men then did; yet Christ in his Spirit, in his word, in his ministers, is still no better treated. And it is just with God to give those up to their hearts' lusts, who obstinately persist in gratifying them. Christ gives men their true characters.