Be surety for thy servant for good - On the meaning of the word here rendered “be surety,” see the notes at Job 17:3, and the notes at Isaiah 38:14, in both which places the same Hebrew word occurs: In Isaiah it is rendered “undertake for me.” The word means, properly, “to mix, to mingle;” hence, to braid, to interweave; then, to exchange, to barter. Then it means to mix or intermingle interests; to unite ourselves with others so that their interests come to be our own; and hence, to take one under our protection, to become answerable for, to be a surety for: as, when one endorses a note for another, he mingles his own interest, reputation, and means with his. So Christ becomes the security or surety - ἔγγυος enguos - of his people, Hebrews 7:22. The prayer here is, that God would, so to speak, mix or mingle his cause and that of the psalmist together, and that he would then protect the common cause as his own; or, that he would become a “pledge” or “surety” for the safety of the psalmist. This now, through the Mediator, we have a right to ask at the hand of God; and when God makes our cause his own, we must be safe.
Let not the proud oppress me - See the notes at Psalms 119:51. Let them not triumph over me, and crush me.