16 Let us therefore love God, brethren, purely and chastely. There is not a chaste heart, if God for reward it worships. How so? Reward of the worship of God shall not we have? We shall have evidently, but it is God Himself whom we worship. Himself for us a reward shall be, because “we shall see Him as He is.” Observe that a reward you shall obtain....I will tell you, brethren: in these human alliances consider a chaste heart, of what sort it is towards God: certainly human alliances are of such sort, that a man does not love his wife, that loves her because of her portion: a woman her husband does not chastely love, that for these reasons loves him, because something he has given, or because much he has given. Both a rich man is a husband, and one that has become a poor man is a husband. How many men proscribed, by chaste wives have been the more beloved! Proved have been many chaste marriages by the misfortunes of husbands: that the wives might not be supposed to love any other object more than their husband, not only have they not forsaken, but the more have they obeyed. If therefore a husband of flesh freely is loved, if chastely he is loved; and a wife of flesh freely is loved, if chastely she is loved; in what manner must God be loved, the true and truth-speaking Husband of the soul, making fruitful unto the offspring of everlasting life, and not suffering us to be barren? Him, therefore, so let us love, as that any other thing besides Himself be not loved: and there takes place in us that which we have spoken of, that which we have sung, because even here the voice is ours: “In whatsoever day I shall have called upon You, behold, I have known that my God are You.” This is to call upon God, freely to call upon Him. Furthermore, of certain men has been said what? “Upon the Lord they have not called.” The Lord they seemed as it were to call unto themselves and they besought Him about inheritances, about increasing money, about lengthening this life, about the rest of temporal things: and concerning them the Scripture says what? “Upon the Lord they have not called.” Therefore there follows what? “There they have feared with fear, where there was no fear.” What is, “where there was no fear”? Lest money should be stolen from them, lest anything in their house should be made less; lastly, lest they should have less of years in this life, than they hoped for themselves: but there have they trembled with fear, where there was no fear....“In God I will praise the word, in the Lord I will praise the discourse”: “in God I have hoped, I will not fear what man does unto me”. Now this is the very sense which above has been repeated.
17. “In me, O God, are Your vows, which I will render of praise to You”. “Vow ye, and render to the Lord your God.” What vow, what render? Perchance those animals which were offered at the altars aforetime? No such thing offer thou: in yourself is what you may vow and render. From the heart's coffer bring forth the incense of praise; from the store of a good conscience bring forth the sacrifice of faith. Whatsoever thing you bring forth, kindle with love. In yourself be the vows, which you may render of praise to God. Of what praise? For what has He granted you? “For You have rescued my soul from death”. This is that very life which he tells out to Him: “O God, my life I have told out to You.” For I was what? Dead. Through myself I was dead: through You I am what? Alive. Therefore “in me, O God, are Your vows, which I will render of praise to You.” Behold I love my God: no one does tear Him from me: that which to Him I may give, no one does tear from me, because in the heart it is shut up. With reason is said with that former confidence, “What should man do unto me?” Let man rage, let him be permitted to rage, be permitted to accomplish that which he attempts: what is he to take away? Gold, silver, cattle, men servants, maid servants, estates, houses, let him take away all things: does he by any means take away the vows, which are in me, which I may render of praise to God? The tempter was permitted to tempt a holy man, Job; in one moment he took away all things: whatever of possessions he had had, he carried off: took away inheritance, slew heirs; and this not little by little, but in a crowd, at one blow, at one swoop, so that all things were on a sudden announced: when all was taken away, alone there remained Job, but in him were vows of praise, which he might render to God, in him evidently there were: the coffer of his holy breast the thieving devil had not rifled, full he was of that wherefrom he might sacrifice. Hear what he had, hear what he brought forth: “The Lord has given, the Lord has taken away; as has pleased the Lord, so has been done: be the name of the Lord blessed.” O riches interior, whither thief does not draw near! God Himself had given that whereof He was receiving; He had Himself enriched him with that whereof to Him he was offering that which He loved. Praise from you God requires, your confession God requires. But from your field will you give anything? He has Himself rained in order that you may have. From your coffer will you give anything? He has Himself put in that which you are to give. What will you give, which from Him you have not received? “For what have you which you have not received?” From the heart will you give? He too has given faith, hope, and charity: this you must bring forth: this you must sacrifice. But evidently all the other things the enemy is able to take away against your will; this to take away he is not able, unless thou be willing. These things a man will lose even against his will: and wishing to have gold, will lose gold; and wishing to have house, will lose house: faith no one will lose, except him that shall have despised her.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)