"You shall not commit adultery.
Exodus 20:14 and Deuteronomy 5:18

'The man who commits adultery with [another] man's wife, [he] who commits adultery with his neighbor's wife, the adulterer and the adulteress, shall surely be put to death.
Leviticus 20:10

Whoever commits adultery with a woman lacks understanding; He [who] does so destroys his own soul.
Proverbs 6:32

Then I saw that for all the causes for which backsliding Israel had committed adultery, I had put her away and given her a certificate of divorce; yet her treacherous sister Judah did not fear, but went and played the harlot also. So it came to pass, through her casual harlotry, that she defiled the land and committed adultery with stones and trees.
Jeremiah 3:8-9

"How shall I pardon you for this? Your children have forsaken Me And sworn by [those] [that are] not gods. When I had fed them to the full, Then they committed adultery And assembled themselves by troops in the harlots' houses. They were [like] well-fed lusty stallions; Every one neighed after his neighbor's wife. Shall I not punish [them] for these [things]?" says the LORD. "And shall I not avenge Myself on such a nation as this?
Jeremiah 5:7-9

Will you steal, murder, commit adultery, swear falsely, burn incense to Baal, and walk after other gods whom you do not know, and [then] come and stand before Me in this house which is called by My name, and say, 'We are delivered to do all these abominations'?
Jeremiah 7:9-10

Also I have seen a horrible thing in the prophets of Jerusalem: They commit adultery and walk in lies; They also strengthen the hands of evildoers, So that no one turns back from his wickedness. All of them are like Sodom to Me, And her inhabitants like Gomorrah. "Therefore thus says the LORD of hosts concerning the prophets: 'Behold, I will feed them with wormwood, And make them drink the water of gall; For from the prophets of Jerusalem Profaneness has gone out into all the land.' " Thus says the LORD of hosts: "Do not listen to the words of the prophets who prophesy to you. They make you worthless; They speak a vision of their own heart, Not from the mouth of the LORD.
Jeremiah 23:14-16

And because of them a curse shall be taken up by all the captivity of Judah who [are] in Babylon, saying, "The LORD make you like Zedekiah and Ahab, whom the king of Babylon roasted in the fire"; because they have done disgraceful things in Israel, have committed adultery with their neighbors' wives, and have spoken lying words in My name, which I have not commanded them. Indeed I know, and [am] a witness, says the LORD.
Jeremiah 29:22-23

For they have committed adultery, and blood [is] on their hands. They have committed adultery with their idols, and even sacrificed their sons whom they bore to Me, passing them through [the fire], to devour [them].
Ezekiel 23:37

Then the LORD said to me, "Go again, love a woman who is loved by a lover and is committing adultery, just like the love of the LORD for the children of Israel, who look to other gods and love the raisin cakes of the pagans."
Hosea 3:1

[By] swearing and lying, Killing and stealing and committing adultery, They break all restraint, With bloodshed upon bloodshed. Therefore the land will mourn; And everyone who dwells there will waste away With the beasts of the field And the birds of the air; Even the fish of the sea will be taken away. . .

They offer sacrifices on the mountaintops, And burn incense on the hills, Under oaks, poplars, and terebinths, Because their shade [is] good. Therefore your daughters commit harlotry, And your brides commit adultery. "I will not punish your daughters when they commit harlotry, Nor your brides when they commit adultery; For [the men] themselves go apart with harlots, And offer sacrifices with a ritual harlot. "Though you, Israel, play the harlot, Let not Judah offend. Do not come up to Gilgal, Nor go up to Beth Aven, Nor swear an oath, [saying], 'As the LORD lives'--Therefore people [who] do not understand will be trampled. . . Their drink is rebellion, They commit harlotry continually. Her rulers dearly [fn] love dishonor.
Hosea 4:2-3, 13-15, 18

"You have heard that it was said to those of old, 'You shall not commit adultery.' But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart.

If your right eye causes you to sin, pluck it out and cast [it] from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell. And if your right hand causes you to sin, cut it off and cast [it] from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell.

"Furthermore it has been said, 'Whoever divorces his wife, let him give her a certificate of divorce.' But I say to you that whoever divorces his wife for any reason except sexual immorality [fn] causes her to commit adultery; and whoever marries a woman who is divorced commits adultery.
Matthew 5:27-32

And I say to you, whoever divorces his wife, except for sexual immorality, and marries another, commits adultery; and whoever marries her who is divorced commits adultery." ...So He said to him, "Why do you call Me good? No one [is] good but One, [that is], God. But if you want to enter into life, keep the commandments." He said to Him, "Which ones?" Jesus said, "'You shall not murder,' 'You shall not commit adultery,' 'You shall not steal,' 'You shall not bear false witness,'
Matthew 19:9, 17-18

So He said to them, "Whoever divorces his wife and marries another commits adultery against her. And if a woman divorces her husband and marries another, she commits adultery." ...You know the commandments: 'Do not commit adultery,' 'Do not murder,' 'Do not steal,' 'Do not bear false witness,' 'Do not defraud,' 'Honor your father and your mother.' "
Mark 10:11-12, 19

"Whoever divorces his wife and marries another commits adultery; and whoever marries her who is divorced from [her] husband commits adultery.
Luke 16:18

You know the commandments: 'Do not commit adultery,' 'Do not murder,' 'Do not steal,' 'Do not bear false witness,' 'Honor your father and your mother.' "
Luke 18:20

Then the scribes and Pharisees brought to Him a woman caught in adultery. And when they had set her in the midst, they said to Him, "Teacher, this woman was caught in adultery, in the very act.
John 8:3-4

You who say, "Do not commit adultery," do you commit adultery? You who abhor idols, do you rob temples?
Romans 2:22

For the commandments, "You shall not commit adultery," "You shall not murder," "You shall not steal," "You shall not bear false witness," "You shall not covet," and if [there is] any other commandment, are [all] summed up in this saying, namely, "You shall love your neighbor as yourself."
Romans 13:9

Now the works of the flesh are evident, which are: adultery, fornication, uncleanness, lewdness, idolatry, sorcery, hatred, contentions, jealousies, outbursts of wrath, selfish ambitions, dissensions, heresies, envy, murders, drunkenness, revelries, and the like; of which I tell you beforehand, just as I also told [you] in time past, that those who practice such things will not inherit the kingdom of God.
Galatians 5:19-21

For He who said, "Do not commit adultery," also said, "Do not murder." Now if you do not commit adultery, but you do murder, you have become a transgressor of the law.
James 2:11

But these, like natural brute beasts made to be caught and destroyed, speak evil of the things they do not understand, and will utterly perish in their own corruption, [and] will receive the wages of unrighteousness, [as] those who count it pleasure to carouse in the daytime. [They are] spots and blemishes, carousing in their own deceptions while they feast with you, having eyes full of adultery and that cannot cease from sin, enticing unstable souls. [They have] a heart trained in covetous practices, [and are] accursed children.
2 Peter 2:12-14

Nevertheless I have a few things against you, because you allow that woman Jezebel, who calls herself a prophetess, to teach and seduce My servants to commit sexual immorality and eat things sacrificed to idols. And I gave her time to repent of her sexual immorality, and she did not repent. Indeed I will cast her into a sickbed, and those who commit adultery with her into great tribulation, unless they repent of their deeds. I will kill her children with death, and all the churches shall know that I am He who searches the minds and hearts. And I will give to each one of you according to your works.
Revelation 2:20-23