regarding the Divine Verse: "O you who believe! You are forbidden to inherit women against their will, and you should not treat them with harshness that you may take back part of the (Mahr) dower you have given them." (4.19) (Before this revelation) if a man died, his relatives used to have the right to inherit his wife, and one of them could marry her if he wished, or they would give her (to someone else) in marriage if they wished, or, if they wished, they would not give her in marriage at all, and they would be more entitled to dispose her, than her own relatives. So the above Verse was revealed in this connection.
Lessons
1. Allah abolished the ancient semitic (jewish) and pagan custom of inheriting the widow of your relative and using her as they wish.
2. Allah also prohibited treating the widows with harshness and take back the dowry amount which they had once received
3. Allah abolished the false notion that the relative of the women have less or no right over her than the relative of her dead husband.