Matthew 12:36-37 (KJV)
36 But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment.
37 For by thy words thou shalt be justified, and by thy words thou shalt be condemned.
Ephesians 4:29 (KJV)
29 Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.
Ephesians 5:4 (KJV)
4 Neither filthiness, nor foolish talking, nor jesting, which are not convenient: but rather giving of thanks.
Ephesians 5:4 (ESV)
4 Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving.
Colossians 3:8-9 (KJV)
8 But now ye also put off all these; anger, wrath, malice, blasphemy, filthy communication out of your mouth.
9 Lie not one to another, seeing that ye have put off the old man with his deeds;
Ephesians 4:31 (KJV)
31 Let all bitterness, and wrath, and anger, and clamour, and evil speaking, be put away from you, with all malice:
1 Corinthians 10:10 (KJV)
10 Neither murmur ye, as some of them also murmured, and were destroyed of the destroyer.
1 Thessalonians 5:16-18 (KJV)
16 Rejoice evermore.
17 Pray without ceasing.
18 In every thing give thanks: for this is the will of God in Christ Jesus concerning you.