James 3:10

Out of the same mouth flow blessing and cursing! It ought not to be like this, my brothers.

Romans 12:14

Keep on blessing your persecutors; keep on blessing and stop cursing them.

1 Corinthians 3:3

for you are still unspiritual. For when there are still jealousy and wrangling among you, are you not still unspiritual and living by a human standard?

1 Timothy 5:13

Besides, as they get the habit of gadding about from house to house, they learn to be idle, and not only idle but gossips and busybodies, talking of things they ought not to mention.

1 Peter 3:9

never returning evil for evil or abuse for abuse, but blessing instead, because it was for this that you were called, to obtain the blessing of heirs.

Treasury of Scripture Knowledge

Summary

Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.

Bible References

Of

Romans 12:14
Keep on blessing your persecutors; keep on blessing and stop cursing them.
1 Peter 3:9
never returning evil for evil or abuse for abuse, but blessing instead, because it was for this that you were called, to obtain the blessing of heirs.

These

1 Corinthians 3:3
for you are still unspiritual. For when there are still jealousy and wrangling among you, are you not still unspiritual and living by a human standard?
1 Timothy 5:13
Besides, as they get the habit of gadding about from house to house, they learn to be idle, and not only idle but gossips and busybodies, talking of things they ought not to mention.

General references

Matthew 15:18
But the things that come out of the mouth come from the heart, and they make the man foul.
Romans 3:14
Their mouths are full of bitter cursing.
Romans 12:14
Keep on blessing your persecutors; keep on blessing and stop cursing them.