James 3:10

blessing and cursing stream from the same lips! My brothers, this ought not to be.

Romans 12:14

Bless those who make a practice of persecuting you; bless them instead of cursing them.

1 Corinthians 3:3

you are still worldly. For with jealousy and quarrels in your midst, are you not worldly, are you not behaving like ordinary men?

1 Timothy 5:13

Besides, they become idle unconsciously by gadding about from one house to another ??and not merely idle but gossips and busybodies, repeating things they have no right to mention.

1 Peter 3:9

never paying back evil for evil, never reviling when you are reviled, but on the contrary blessing. For this is your vocation, to bless and to inherit 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 those who make a practice of persecuting you; bless them instead of cursing them.
1 Peter 3:9
never paying back evil for evil, never reviling when you are reviled, but on the contrary blessing. For this is your vocation, to bless and to inherit blessing;

These

1 Corinthians 3:3
you are still worldly. For with jealousy and quarrels in your midst, are you not worldly, are you not behaving like ordinary men?
1 Timothy 5:13
Besides, they become idle unconsciously by gadding about from one house to another ??and not merely idle but gossips and busybodies, repeating things they have no right to mention.

General references

Matthew 15:18
while what comes out of the mouth comes from the heart ??and that is what defiles a man.
Romans 3:14
Their mouth is full of cursing and bitterness,
Romans 12:14
Bless those who make a practice of persecuting you; bless them instead of cursing them.