Psalm 19:7

The law of the LORD is perfect, refreshing the soul. The statutes of the LORD are trustworthy, making wise the simple.

The law of the LORD 
Psalm 1:1-2  Blessed is the one who does not walk in step with the wicked or stand in the way that sinners take or sit in the company of mockers, but whose delight is in the law of the LORD, and who meditates on his law day and night.

is perfect 
Psalm 119:142  Your righteousness is everlasting and your law is true.
James 1:25  But whoever looks intently into the perfect law that gives freedom, and continues in it--not forgetting what they have heard, but doing it--they will be blessed in what they do.

refreshing the soul 
Psalm 23:2-3  He makes me lie down in green pastures, he leads me beside quiet waters, he refreshes my soul. He guides me along the right paths for his name's sake.

The statutes of the LORD are trustworthy 
Psalm 93:5  Your statutes, LORD, stand firm; holiness adorns your house for endless days.
Psalm 111:7  The works of his hands are faithful and just; all his precepts are trustworthy.
Psalm 119:138  The statutes you have laid down are righteous; they are fully trustworthy.
Psalm 119:144  Your statutes are always righteous; give me understanding that I may live.

making wise the simple 
Deuteronomy 4:5-7  See, I have taught you decrees and laws as the LORD my God commanded me, so that you may follow them in the land you are entering to take possession of it. Observe them carefully, for this will show your wisdom and understanding to the nations, who will hear about all these decrees and say, "Surely this great nation is a wise and understanding people." What other nation is so great as to have their gods near them the way the LORD our God is near us whenever we pray to him?
Psalm 119:130  The unfolding of your words gives light; it gives understanding to the simple.

Scriptures taken from the Holy Bible, New International Version® NIV®, Copyright© 1973, 1978, 1984, 2011 by Biblica, Inc.® Used by permission. All rights reserved worldwide. 
Limited to 15 verses per post.