11. And thou shalt require. On another ground he exhorts and excites them to willingness, because the service of God brings this rejoicing; for there is nothing which ought more to stimulate us to obedience, that when we know that God rather consults our good than seeks to obtain any advantage from us. Ungodly men, indeed, rejoice also, nay, they are wanton and intemperate in their joy; but since that joy is not only transient, but their laughter is turned into weeping and gnashing of teeth, it is not without cause that Moses here magnifies it as a peculiar blessing, to rejoice before God; as if a father should invite his children to delight themselves together with him. But by this external exercise, believers were reminded that there is no real or desirable joy, unless in reference to God. And surely, however the wicked may exult in their pleasures, and abandon themselves to gratifcations, still, since tranquillity of conscience, which alone brings true rejoicing, is wanting to them, they do not enjoy the merriment into which they plunge themselves. Finally, Moses amplifies by a comparison the good which they enjoyed in the service of God, when he says, “And thou shalt remember that thou wast a bondman in Egypt;” for that their present condition might be more pleasant to them, he heightened its sweetness by the recollection of their most miserable captivity. I have here neglected Cicero’s (360) very subtle distinction between the words gaudium and laetitia, for unless I take both of them in a good sense, I could not translate the Hebrew words, whereby God would express how indulgently He deals with His children. Meanwhile, this passage contains an exhortation to render thanks to God our deliverer.
(360) Tusc. Quoest iv., “ Nam cum ratione animus movetur placide et constanter, tum illud gaudium dicitur; cum autem inaniter, et effuse animus exultat, tum ilia laetitia gestiens, vel nimia dici potest; quam ita definiunt, sine ratione animi elationem.” — Edit. Elz., 1661, p. 1088, a.