Charles H. Spurgeon on Psalms 119:81

This portion of the gigantic psalm sees the Psalmist in extremis. His enemies have brought him to the lowest condition of anguish and depression; yet he is faithful to the law and trustful in his God. This octave is the midnight of the psalm, and very dark and black it is. Stars, however, shine out, and the last verse gives promise of the dawn. The strain will after this become more cheerful; but meanwhile it should minister comfort to us to see so eminent a servant of God so hardly used by the ungodly: evidently in our own persecutions, no strange thing has happened unto us.

My soul fainteth for thy salvation. He wished for no deliverance but that which came from God: his one desire was for "thy salvation." But for that divine deliverance he was eager to the last degree, up to the full measure of his strength, yea, and beyond it till he fainted. So strong was his desire that it produced prostration of spirit. He grew weary with waiting, faint with watching, sick with urgent need. Thus the sincerity and the eagerness of his desires were proved. Nothing else could satisfy him but deliverance wrought out by the hand of God, his inmost mature yearned and pined for salvation from the God of all grace, and he must have it or utterly fail.

But I hope in thy word. Therefore he felt that salvation would come, for God cannot break his promise, nor disappoint the hope which his own word has excited: yea, the fulfilment of his word is near at hand when our hope is firm and our desire fervent. Hope alone can keep the soul from fainting by using the smelling bottle of the promise. Yet hope does not quench desire for a speedy answer to prayer; it increases our importunity, for it both stimulates ardour and sustains the heart under delays. To faint for salvation, and to be kept from utterly failing by the hope of it, is the frequent experience of the Christian man. We are "faint yet pursuing" hope sustains when desire exhausts. While the grace of desire throws us down, the grace of hope lifts us up again.