God says
O mankind! Partake of what is lawful and good on earth, and follow not Satan’s footsteps for he is your avowed enemy, and bids you only to do what is evil and to commit deeds which are shameful, …. Q.2:168,169
[Say: “Come, let me convey unto you what God has (really) forbidden you:] ….. and do not commit any shameful deeds, be they open or secret;…. Q.6:151
… [God] forbids all that is shameful and all that runs counter to reason [that which the moral sense rejects]….. Q.16:90
*The term al-munkar has here its original meaning of “that which the mind [or the moral sense] rejects, respectively “ought to reject.” Zamakhshari is more specific and explains this term as signifying in the above context “that which intellects disown” or “declare to be untrue”: fully in tune with the rational approach of the Quran to questions of ethics as well as with its insistence on reasonableness and moderation in man’s behavior.
Do not come near adultery*-- for it is an abomination and an evil that opens the road (to other evils). -- Q.17:32
* “Nor come near adultery” thus intensifying the prohibition. It is to be noted that the term zina signifies all sexual intercourse between a man and a woman who are not husband and wife, irrespective of whether either of them is married to another partner or not; hence, it denotes both “adultery” and “fornication” in the English terms.
Prophet said
1. “Indecency only brings disgrace wherein it occurs”– H: Tirmizi. N: Anas.