I have taken an oath and confirmed it, that I will follow your righteous laws.
NIV
I have sworn [an oath] and have confirmed it, that I will keep Your righteous ordinances [hearing, receiving, loving, and obeying them]. [Neh. 10:29.]AMP
I have sworn, and I will perform it, that I will keep thy righteous judgments.
KJV
Fulfill your promise to your servant, so that you may be feared.
NIV
Establish Your word and confirm Your promise to Your servant, which is for those who reverently fear and devotedly worship You. [Deut. 10:12; Ps. 96:9.]AMP
Stablish thy word unto thy servant, who is devoted to thy fear.
KJV