Leviticus 15:4
"Every bed, whereon he lieth that hath the issue, is unclean: and every thing, whereon he sitteth, shall be unclean."
Cross References (ranked by relevance)
1 Corinthians 15:33
Be not deceived: evil communications corrupt good manners.
Titus 1:15
Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled.
Ephesians 5:11
And have no fellowship with the unfruitful works of darkness, but rather reprove them.