7 The law of the Lord is perfect, restoring the soul;
The testimony of the Lord is sure, making wise the simple.
A “testimony of the Lord” is a Biblical account of God’s dealing with someone in accordance with His nature and His ways. While those accounts often do not specifically outline the Biblical principles at play, they are excellent illustrations of truth gleaned in other parts of the Bible. A “case study” or a “cautionary tale” might be modern ways of referring to these accounts. And as Psalm 19:7 and I Corinthians 10:11 state, these accounts can provide wisdom to those who are naive (or simple).
One such account is that of Eliab, David’s oldest brother.
1 Chronicles 2:13-15
13 and Jesse became the father of Eliab his firstborn, then Abinadab the second, Shimea the third, 14 Nethanel the fourth, Raddai the fifth, 15 Ozem the sixth, David the seventh;