Parallel
Psalms 39:9
Swete's Septuagint · Berean Standard Bible
τοῦ ποιῆσαι τὸ θέλημά σου ὁ θεός μου ἐβουλήθην, καὶ τὸν νόμον σου ἐν μέσῳ τῆς καρδίας μου.
40:8
I delight to do Your will, O my God (note: Cited in Hebrews 10:5–7); Your law is within my heart.”