Psalms 40:16

16.Let all those that seek thee be glad and rejoice in thee. David here uses another argument — one which he often adduces elsewhere — in order to obtain deliverance; not that it is necessary to allege reasons to persuade God, but because it is profitable to confirm our faith by such supports. As, then, it is the will of God that he should be known in his gracious character, not only of one or two, but generality of all men, whenever he vouchsafes deliverance to any of his children, it is a common benefit which all the faithful ought to apply to themselves when they see in the person of one man in what manner God, who is never inconsistent with himself, will act towards all his people. David, therefore, shows that he asks nothing for himself individually but what pertains to the whole Church. He prays that God would gladden the hearts of all the saints, or afford them all common cause of rejoicing: so that, assured of his readiness to help them, they may have recourse to him with greater alacrity. Hence we conclude, that, in the case of every individual, God gives a proof of his goodness towards us. What is added, those that love thy salvation, is also worthy of being observed by us. We may infer from this, that our faith is only proved to be genuine when we neither expect nor desire preservation otherwise than from God alone. Those who devise various ways and means of preservation for themselves in this world, despise and reject the salvation which God has taught us to expect from him alone. What had been said before, those who seek thee, is to the same purpose. If any individual would depend wholly upon God, and desire to be saved by his grace, he must renounce every vain hope, and employ all his thoughts towards the reception of his strength. Here, again, we must observe that two things are contrasted with each other. Formerly David had said that the wicked sought his life; now he ascribes to the faithful quite a contrary feeling, namely, that they seek God. In like manner he had related the reproaches and derision of the ungodly, while they said, Aha, aha! and now he introduces the godly speaking very differently, saying, The Lord be magnified!