And those of your women who commit illegal sexual intercourse, take the evidence of four witnesses from amongst you against them; and if they testify, confine them (i.e. women) to houses until death comes to them or Allah ordains for them some (other) way.

And the two persons (man and woman) among you who commit illegal sexual intercourse, punish them both. And if they repent (promise Allah that they will never repeat, i.e. commit illegal sexual intercourse and other similar sins) and do righteous good deeds, leave them alone. Surely, Allah is Ever the One Who accepts repentance, (and He is) Most Merciful.