Colossians 4:5

Be wise in the way you live in front of outsiders [i.e., non-Christians], making the most of every opportunity.

Hebrews 2:1

So [then], we [Christians] should pay closer attention to the things we have heard, so that we do not drift away from [believing and practicing] them.

James 1:26

If anyone considers himself to be religious and yet does not keep a tight rein on his tongue, this person is self-deceived and his religion is worthless.

James 3:2-8

For we all make mistakes in many areas [of life]. If anyone does not make a mistake in what he says, he is a perfect person, capable of keeping a tight rein on his whole life also.

Treasury of Scripture Knowledge

Summary

{To the chief Musician, even to Jeduthun, A Psalm of David.} I said, I will take heed to my ways, that I sin not with my tongue: I will keep my mouth with a bridle, while the wicked is before me.

I said

My mouth, etc

General references

Bible References

I said

Hebrews 2:1
So [then], we [Christians] should pay closer attention to the things we have heard, so that we do not drift away from [believing and practicing] them.

My mouth, etc

James 1:26
If anyone considers himself to be religious and yet does not keep a tight rein on his tongue, this person is self-deceived and his religion is worthless.
James 3:2
For we all make mistakes in many areas [of life]. If anyone does not make a mistake in what he says, he is a perfect person, capable of keeping a tight rein on his whole life also.

While

Colossians 4:5
Be wise in the way you live in front of outsiders [i.e., non-Christians], making the most of every opportunity.

General references

James 3:3
Now if we put bits in the mouths of horses so that they will obey us, we can govern the direction of their entire bodies as well.