James 3:10

Out of the same mouth goeth forth blessing and cursing. These things, my brethren, ought not to be thus.

Romans 12:14

Bless them who persecute you; bless, and curse not.

1 Corinthians 3:3

For ye are still carnal: for since there are among you envy, and strife, and divisions, are ye not carnal, and walk as [other] men?

1 Timothy 5:13

And at the same time also they learn to be idle, visiting about in the houses; and not merely idle, but talkative and inquisitive, speaking things they ought not.

1 Peter 3:9

not returning evil for evil, or railing for railing; but, contrariwise, wishing men every blessing; knowing that hereunto ye have been called, that ye should inherit the [divine] benediction.

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 who persecute you; bless, and curse not.
1 Peter 3:9
not returning evil for evil, or railing for railing; but, contrariwise, wishing men every blessing; knowing that hereunto ye have been called, that ye should inherit the [divine] benediction.

These

1 Corinthians 3:3
For ye are still carnal: for since there are among you envy, and strife, and divisions, are ye not carnal, and walk as [other] men?
1 Timothy 5:13
And at the same time also they learn to be idle, visiting about in the houses; and not merely idle, but talkative and inquisitive, speaking things they ought not.

General references

Matthew 15:18
But the things which go forth out of the mouth, come out of the heart, and they are the things which defile a man:
Romans 3:14
whose mouth is full of cursing and bitterness:
Romans 12:14
Bless them who persecute you; bless, and curse not.