James 3:10

From the very same mouth come blessings and curses! My Brothers, it is not right that this should be so.

Romans 12:14

Bless your persecutors--bless and never curse.

1 Corinthians 3:3

While there exist among you jealousy and party feeling, is it not true that you are worldly, and are acting merely as other men do?

1 Timothy 5:13

And not only that, but they learn to be idle as they go about from house to house. Nor are they merely idle, but they also become gossips and busy-bodies, and talk of what they ought not.

1 Peter 3:9

never returning evil for evil, or abuse for abuse, but, on the contrary, blessing. It was to this that you were called--to obtain a blessing!

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
Bless your persecutors--bless and never curse.
1 Peter 3:9
never returning evil for evil, or abuse for abuse, but, on the contrary, blessing. It was to this that you were called--to obtain a blessing!

These

1 Corinthians 3:3
While there exist among you jealousy and party feeling, is it not true that you are worldly, and are acting merely as other men do?
1 Timothy 5:13
And not only that, but they learn to be idle as they go about from house to house. Nor are they merely idle, but they also become gossips and busy-bodies, and talk of what they ought not.

General references

Matthew 15:18
But the things that come out from the mouth proceed from the heart, and it is these that defile a man;
Romans 3:14
'And their mouths are full of bitter curses.'
Romans 12:14
Bless your persecutors--bless and never curse.