We must keep a watch over anything that we speak and think and guard everything that we see, hear, and the company we keep before it is recorded in our heart.

[Psalm 141:3-4] Set a guard, O LORD, over my mouth; Keep watch over the door of my lips. Do not incline my heart to any evil thing, To practice wicked works With men who work iniquity; And do not let me eat of their delicacies.