Barnes New Testament Notes

Verse 34. This generation, etc. This age; this race of men. A generation is about thirty or forty years. The destruction of Jerusalem took place about forty years after this was spoken. See Barnes "Mt 16:28".

Till all these things, etc. Till these things shall receive a full accomplishment. Till events shall take place that shall be a complete fulfillment, if there were nothing farther intended. He does not mean to exclude here the reference to the judgment, but to say that the destruction of Jerusalem would be such as to make appropriate the words of the prediction, were there nothing beyond. So when death was threatened to Adam, the propriety of the threatening would have been seen, and the threatening would have been fulfilled, had men suffered only temporal death. At the same time, the threatening had a fulness of meaning, that would cover also, and justify, eternal death in hell. Thus the words of Christ, describing the destruction of Jerusalem, had a fulness of signification that would meet also the events of the judgment, and whose meaning would not be filled up till the world was closed.