King James Version (KJV)
I have sworn, and I will perform it, that I will keep thy righteous judgments.
Modern English
I have sworn an oath and confirmed it, to keep your righteous rules.
Hebrew
נִשְׁבַּ֗עְתִּי וָ֫אֲקַיֵּ֥מָה לִ֭שְׁמֹר מִשְׁפְּטֵ֥י צִדְקֶֽךָ׃
nishbaʿtiy vaʾaqayemah lishmor mishpṭey ṣidqeka