Charles H. Spurgeon on Psalms 119:154

Plead my cause, and deliver me, etc. In this verse are three requests, and all backed with one and the same argument. In the first, he intimates the right of his and that he was unjustly vexed by wicked cause, men; therefore, as burdened with their calumnies, he desireth God to undertake his defence: "Plead my cause." In the second, he represents the misery and helplessness of his condition; therefore, as oppressed by violence, he saith, "Deliver me; "or, as the words will bear, "Redeem me". In the third, his own weakness, and readiness to faint under this burden; therefore he saith, "Quicken me."

Or, in short, with respect to the injustice of his adversaries, "Plead my cause; "with respect to the misery of his own condition, "Deliver me; "with respect to the weakness and imbecility of his own heart, "Quicken me."

The reason and ground of asking, "According to thy word." This last clause must be applied to all the branches of the prayer: "Plead my cause, ""according to thy word; ""deliver me, ""according to thy word; ""quicken me, ""according to thy word:" for God in his word engages for all: to be advocate, Redeemer, and fountain of life. The word that David buildeth upon was found either in the general promises made to them that kept the law, or in some particular promise made to himself by the prophets of that time. Thomas Manton.