James 3:10

from the same mouth shall blessing and cursing proceed? this ought not to be practis'd, my brethren;

Romans 12:14

bless them who persecute you:

1 Corinthians 3:3

for you are still subject to your passions. since envy, and strife, and divisions are among you, are you not actuated by the vices of the animal part?

1 Timothy 5:13

besides, having nothing to do, they get the habit of rambling from one house to another, and are not only idling, but prattle and intermeddle, and utter what is not decent.

1 Peter 3:9

don't return evil for evil, nor calumny for calumny; on the contrary, bestow your benedictions, considering that your vocation obliges you thereto, as a means to obtain the divine 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 who persecute you:
1 Peter 3:9
don't return evil for evil, nor calumny for calumny; on the contrary, bestow your benedictions, considering that your vocation obliges you thereto, as a means to obtain the divine blessing.

These

1 Corinthians 3:3
for you are still subject to your passions. since envy, and strife, and divisions are among you, are you not actuated by the vices of the animal part?
1 Timothy 5:13
besides, having nothing to do, they get the habit of rambling from one house to another, and are not only idling, but prattle and intermeddle, and utter what is not decent.

General references

Matthew 15:18
but what proceeds out of the mouth, is deriv'd from the heart, and that defiles the man.
Romans 3:14
whose mouth is full of cursing and bitterness.
Romans 12:14
bless them who persecute you: