Quran 24:13 — Light (Al-Noor)

Only if they produced four witnesses (you may believe them). If they fail to produce the witnesses, then they are, according to GOD, liars.

[24:12] When you heard it, the believing men and the believing women should have had better thoughts about themselves, and should have said, "This is obviously a big lie."

[24:14] If it were not for GOD's grace towards you, and His mercy in this world and in the Hereafter, you would have suffered a great retribution because of this incident.