Zina

Zināʾ (زِنَاء) or zinā (زِنًى or زِنًا) is an Islamic legal term referring to unlawful sexual intercourse.

Quran

• As for those of your women who are guilty of lewdness, call to witness four of you against them. And if they testify (to the truth of the allegation) then confine them to the houses until death take them or (until) Allah appoint for them a way (through new legislation).
  • Quran 4:15 M. M. Pickthall

• And as for the two of you who are guilty thereof, punish them both. And if they repent and improve, then let them be. Lo! Allah is ever relenting, Merciful.
  • Quran 4:16 M. M. Pickthall

• As for female and male fornicators, give each of them one hundred lashes, and do not let pity for them make you lenient in ˹enforcing˺ the law of Allah, if you ˹truly˺ believe in Allah and the Last Day. And let a number of believers witness their punishment.
  • — Surah An-Nur 24:2

• Why did they not produce four witnesses? Since they produce not witnesses, they verily are liars in the sight of Allah.
  • Surah An-nur Ayat 13 (24:13 Quran)
  • It is a basis for the fact that it remains part of Islamic law that four male Muslim witnesses must be produced in order to establish a crime of adultery or related indiscretions.