Then the repetition is not without its use; for the Prophet says, On my tower will I stand, on the citadel will I set myself. He does not repeat in other words the same thing, because it is obscure; but in order to remind the faithful, that though they are inclined to sloth, they must yet strive to extricate themselves. And we soon find how slothful we become, except each of us stirs up himself. For when any perplexity takes hold on our minds, we soon succumb to despair. This, then, is the reason why the Prophet, after having spoken of the tower, again mentions the citadel.