Charles H. Spurgeon on Psalms 37:40

And the Lord shall help them. In all future time Jehovah will stand up for his chosen. Our Great Ally will bring up his forces in the heat of the battle. He shall deliver them from the wicked. As he rescued Daniel from the lions, so will he preserve his beloved from their enemies; they need not therefore fret, nor be discouraged. And save them, because they trust in him. Faith shall ensure they safety of the elect. It is the mark of the sheep by which they shall be separated from the goats. Not their merit, but their believing, shall distinguish them. Who would not try the walk of faith? Whoever truly believes in God will be no longer fretful against the apparent irregularities of this present life, but will rest assured that what is mysterious is nevertheless just, and what seems hard, is, beyond a doubt, ordered in mercy. So the Psalm ends with a note which is the death knell of the unhallowed disquietude with which the Psalm commenced. Happy they who can thus sing themselves out of ill frames into gracious conditions.