Matthew 12:36-37

But I tell you that for every careless word that men shall speak they will be held accountable on the day of Judgement.

Colossians 4:6

Let your language be always seasoned with the salt of grace, so that you may know how to give every man a fitting answer.

1 Timothy 6:4-5

he is puffed up with pride and has no true knowledge, but is crazy over discussions and controversies about words which give rise to envy, quarrelling, revilings, ill-natured suspicions,

Treasury of Scripture Knowledge

Summary

Should he reason with unprofitable talk? or with speeches wherewith he can do no good?

Bible References

He reason

Matthew 12:36
But I tell you that for every careless word that men shall speak they will be held accountable on the day of Judgement.
Colossians 4:6
Let your language be always seasoned with the salt of grace, so that you may know how to give every man a fitting answer.
1 Timothy 6:4
he is puffed up with pride and has no true knowledge, but is crazy over discussions and controversies about words which give rise to envy, quarrelling, revilings, ill-natured suspicions,