In my studies of verses that linked Truth and Grace together, I was amazed that most of those verses were from David and his son Solomon. He understood God's intricate nature and the delicate balance of Truth and Grace, and then passed that learning on to his wise son.
David characterized God (Ps 89:14) and Solomon exhorted us to have it characterize ourselves (Pr 3:3). Solomon wrote that atonement comes from it (Pr 16:6). Both have said it was what preserves them (Ps 61:7 and Pr 20:28). It was the source of David's praise (Ps 138:2). And finally, when David blessed others (in especially difficult circumstances , he wished them Mercy and Truth (2 Sam 15:20).
What an example. They have not been perfect - far from it. But they have understood this particular aspect of God that was later reflected in Christ (John 1:14, 17).