Muqatil bin Hayyan (may Allah have mercy on him) said regarding the saying of Allah Almighty: "O you who believe! It is not lawful for you to inherit women by force." [Surah al-Nisa': 19]: In the Jahiliyyah, when a man died, the heirs of the deceased would throw a cloth over his wife and thereby become heirs to her marriage, and they would have the greater right to marry her. Allah Almighty revealed this verse: "And do not restrain them so that you may take away part of what you have given them." [Surah al-Nisa': 19], that is, the mahr. A man would restrain a woman even though he had no need of her, intending only (that she pay) a ransom. This is the saying of Allah Almighty: "And do not restrain them." He said: Do not prevent them, or do not hold them back. "So that you may take away part of what you have given them": that is, what you have granted them. "Except if they commit a clear immorality" [Surah al-Nisa': 19]: that is, open disobedience. Because of this Allah Almighty has permitted striking and separation, and if she (still) refuses, then ransom also becomes permissible.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13793