An-Nisa 20-23, The Noble Qur'an (Juz'-4, Page-81)

4/An-Nisa-20: And if you wish to replace a wife by another and you have given one of them a heap of gold (as Mahr) then do not take from it anything; would you take it (what you promised) by slandering and manifest sin?

4/An-Nisa-21: And how could you take it while you have gone in unto each other and they have taken from you a solemn covenant?

4/An-Nisa-22: And do not marry women whom your fathers married, except what has already passed; this surely is indecent and hateful and it is an evil way.

4/An-Nisa-23: Forbidden to you (for marriage) are: your mothers, and your daughters, and your sisters; and your father’s sisters and your mother’s sisters, and your brother’s daughters and your sister’s daughters and your foster mothers, and your foster-sisters, and your mothers-in law, and your step-daughters who are under your protection (born) of your women unto whom you have gone in-but if you have not gone in to them, then it is no sin for you (to marry their daughters). And the wives of your sons who (spring) from your own loins, and that you should have two sisters together, except what had already happened in the past. Surely Allah is Oft-Forgiving, Most Merciful.