Psalm 39:1

I said, "I will watch my ways and keep my tongue from sin; I will put a muzzle on my mouth while in the presence of the wicked."

I said, "I will watch my ways ..." 
1 Kings 2:1-4  When the time drew near for David to die, he gave a charge to Solomon his son. "I am about to go the way of all the earth," he said. "So be strong, act like a man, and observe what the LORD your God requires: Walk in obedience to him, and keep his decrees and commands, his laws and regulations, as written in the Law of Moses. Do this so that you may prosper in all you do and wherever you go and that the LORD may keep his promise to me: 'If your descendants watch how they live, and if they walk faithfully before me with all their heart and soul, you will never fail to have a successor on the throne of Israel.' "
Psalm 119:9  How can a young person stay on the path of purity? By living according to your word.
Psalm 119:59  I have considered my ways and have turned my steps to your statutes.
Proverbs 20:11  Even small children are known by their actions, so is their conduct really pure and upright?

and keep my tongue from sin 
Job 1:22  In all this Job did not sin by charging God with wrongdoing.
Psalm 34:13  ... keep your tongue from evil and your lips from telling lies.
James 3:2  We all stumble in many ways. Anyone who is never at fault in what they say is perfect, able to keep their whole body in check.

I will put a muzzle on my mouth 
Job 6:24  "Teach me, and I will be quiet; show me where I have been wrong."
James 1:26-27  Those who consider themselves religious and yet do not keep a tight rein on their tongues deceive themselves, and their religion is worthless. Religion that God our Father accepts as pure and faultless is this: to look after orphans and widows in their distress and to keep oneself from being polluted by the world.

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.