“This incense was to be ‘offered with’ or ‘laid upon’ so as to cover or envelope the ‘prayers of all saints’—yes, all saints, from Able downwards; for this seems to be the gathering into one of all prayers from the beginning, that at length they may be answered (Luke 18:3, 7). Upon the golden altar in front of the throne the prayers of the saints of all ages have been laid; there they have accumulated; the unanswered ‘How longs?’ not forgotten.
“Not one petition, even the poorest or feeblest, has dropped from that altar, or been swept away, or lost in the process of time. All, all are there. In themselves the are poor, having no fragrance; but their intrinsic imperfection cannot change the nature of that altar on which they are laid. There they are preserved— each sigh, each tear, each cry, from child or aged man, from the chief of sinners, from the thief upon the cross, from the chamber of weakness and sorrow, from the crushed spirit and the broken heart—there they are: the groanings that cannot be uttered; the ‘God be merciful to me, a sinner;’ the ‘How long?’ of the tortured martyrs; the moan of the suffering saint upon his tossing sick-bed—there they are: the father’s prayer, ‘Lord, save my child;’ the child’s prayer, ‘Lord, save my father’— there they are: the pleadings for the church of God, for the overthrow of Antichrist, for the binding of satan, for the deliverance of earth, for the consummation of the eternal purpose! Not one cry lost; not one petition gone astray. All there!
“There is no such thing as unanswered prayer. Delay will only add to the fullness of the answer, and increase our joy when it comes. And it will come. He is faithful that promised. He cannot deny Himself.” —Horatius Bonar, in Light & Truth: Revelation (emphasis mine)