An-Nur 24:4

Wallatheena yarmoona almuhsanatithumma lam ya/too bi-arbaAAati shuhadaa fajlidoohumthamaneena jaldatan wala taqbaloo lahum shahadatanabadan waola-ika humu alfasiqoon

And those who accuse chaste women and then do not produce four witnesses - lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient,

Those who accuse the chaste women (of fornication), but they do not produce four witnesses, flog them with eighty stripes and do not accept their any evidence any more. They are the sinners,