James 3:10

out of the same mouth proceedeth blessing and cursing. These things, my brethren, ought not so to be.

Romans 12:14

Bless them that persecute you: bless them, I say, and do not curse them.

1 Corinthians 3:3

Because ye are still carnal: for while there is among you envy and strife and divisions, are ye not carnal, and do ye not walk as men?

1 Timothy 5:13

And withal being idle they learn to go about from house to house: and are not only idle, but tatlers also and busy-bodies, talking of things unbecoming them.

1 Peter 3:9

not returning evil for evil, or reproach for reproach: but on the contrary blessing even those that curse you: knowing ye are called unto this, that ye may 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 them that persecute you: bless them, I say, and do not curse them.
1 Peter 3:9
not returning evil for evil, or reproach for reproach: but on the contrary blessing even those that curse you: knowing ye are called unto this, that ye may obtain a blessing.

These

1 Corinthians 3:3
Because ye are still carnal: for while there is among you envy and strife and divisions, are ye not carnal, and do ye not walk as men?
1 Timothy 5:13
And withal being idle they learn to go about from house to house: and are not only idle, but tatlers also and busy-bodies, talking of things unbecoming them.

General references

Matthew 15:18
But the things, which proceed out of the mouth, come from the heart, and those defile a man.
Romans 3:14
whose mouth is full of cursing and bitterness:
Romans 12:14
Bless them that persecute you: bless them, I say, and do not curse them.