Having pointed out the goal to which we are to advance, he exhorts us to pursue our course, which we do, when we habituate ourselves to selfdenial. And as he compares entering into rest to a straight course, he sets falling in opposition to it, and thus he continues the metaphor in both clauses, at the same time he alludes to the history given by Moses of those who fell in the wilderness, because they were rebellious against God. (Numbers 26:65.) Hence he says, after the same example, signifying as though the punishment for unbelief and obstinacy is there set before us as in a picture; nor is there indeed a doubt but that a similar end awaits us, if there be found in us the same unbelief.
Then, “to fall” means to perish; or to speak more plainly, it is to fall, not as to sin, but as a punishment for it. But the figure corresponds as well with the word to “enter”, as with the sad overthrow of the fathers, by whose example he intended to terrify the Jews.