Thou shalt not commit adultery.
Proverbs 31:3Give not thy strength unto women, nor thy ways to that which destroyeth kings.
Acts 15:20But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
Romans 13:13Let us walk honestly, as in the day; not in rioting and drunkenness, not in chambering and wantonness, not in strife and envying.
Colossians 3:5Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry:
1 Thessalonians 4:3For this is the will of God, even your sanctification, that ye should abstain from fornication: