John Calvin Commentary Lamentations 3:8

"Yea, when I cry, and call for help, he shutteth out my prayer." — Lamentations 3:8 (ASV)

The Prophet describes here the extremity of all evils: that it was of no use to him to cry and to pray. And yet we know that we are called to do this in all our miseries.

The strongest tower is the name of the Lord, to it will the righteous flee and shall be safe. (Proverbs 18:10).

Again,

Whosoever shall call on the name of the Lord shall be saved. (Joel 2:32).

And Scripture is full of testimonies of this kind; that is, that God graciously invites all the faithful to himself:

He shall call upon me, and I will hear him. (Psalms 91:15).

In the day when I call, answer me speedily. (Psalms 102:2).

Before they call, I will answer. (Isaiah 65:24).

In short, there is no need to collect all the passages; but we may be content with this one thing: that when God claims for himself this prerogative—that he answers prayers—he intimates that it is something that cannot be separated from his eternal essence and godhead; that is, that he is ready to hear prayer. Therefore, the Psalmist concludes,

To thee shall all flesh come. (Psalms 65:3).

When, therefore, Jeremiah complains that his prayers were in vain, and without any fruit or effect, it seems strange and inconsistent. But we know that God holds the faithful in suspense, and hears them in such a way as to prove and try their patience, sometimes for a long time. This is the reason why he defers and delays his aid.

It is no wonder, then, that God did not hear the prayers of his servant—that is, according to the judgment of the flesh. For God never rejects his own, nor is he deaf to their prayers and their sighs; but the faithful often speak according to what the flesh judges. So, when the Prophet found that he obtained nothing by prayer, he says that his prayer was shut out, or that the door was closed against him, so that his prayer did not come to God.

Now, this passage is worthy of special notice. For unless God immediately meets us, we become languid, and not only does our ardor in prayer cool, but it is almost extinguished.

Let us, then, bear in mind that though God may not help us soon, yet our prayers are never repudiated by him.

And since we see that the holy fathers experienced the same thing, let us not wonder if the Lord today were to try our faith in the same manner.

Let us, therefore, persevere in calling on him.

And should there be a longer delay, and our complaint be that we are not heard, yet let us proceed in the same course, as we shall see the Prophet did.