John 1:17

For the law was given by Moses, but grace and truth came by Jesus Christ:

Romans 5:20-21

Now the law made some entrance, that the offence might appear to abound; but where sin abounded, grace hath superabounded; that as sin had reigned in death,

Romans 15:8-9

Now Jesus Christ was a minister of the circumcision for the manifestation of the truth of God, to confirm the promises made to the fathers:

Ephesians 1:7

in whom we have redemption through his blood, even the remission of sins, according to the riches of his grace;

Ephesians 2:4-7

But God being rich in mercy, through his great love wherewith He loved us,

Treasury of Scripture Knowledge

Summary

But thou, O Lord, art a God full of compassion, and gracious, longsuffering, and plenteous in mercy and truth.

Bible References

But thou

Romans 5:20
Now the law made some entrance, that the offence might appear to abound; but where sin abounded, grace hath superabounded; that as sin had reigned in death,
Ephesians 1:7
in whom we have redemption through his blood, even the remission of sins, according to the riches of his grace;
Ephesians 2:4
But God being rich in mercy, through his great love wherewith He loved us,