They ask thy instruction concerning the women say: Allah doth instruct you about them: And (remember) what hath been rehearsed unto you in the Book, concerning the orphans of women to whom ye give not the portions prescribed, and yet whom ye desire to marry, as also concerning the children who are weak and oppressed: that ye stand firm for justice to orphans. There is not a good deed which ye do, but Allah is well-acquainted therewith.
Yahiya Emerick writes,
Islam granted automatic inheritance rights to women and to orphans. Pre-Islamic Arab traditions did allow inheritance for these two groups, but the usual practice was for unscrupulous men to seize the inheritance or otherwise play games to keep control of it. Even worse, male relatives could assume control of that inheritance by either “inheriting” the widow or forcibly marrying the orphan girl. One man complained openly in Medina about this change in custom, saying, “How can women and children have the right to inherit when they neither work nor earn a living? Are they going to start inheriting now as if they were men, even though they did not earn that wealth?” After the revelation of verse 4:3, another man, who resented the changing of longstanding Arab customs regarding the permissibility of taking advantage of orphan girls to get at their inheritances, went to the Prophet for clarification. This man, a clan leader named Jabir ibn ‘Abdullah, had an unattractive, blind female cousin under his care, (who had also happened to have inherited a fortune from her deceased father). His plan was to keep her around and prevent her from marrying another so as to keep control of her inheritance. He exclaimed to the Prophet, “Does an ugly, blind girl have the right to inherit?” The Prophet replied, “Yes, most definitely.” Then he recited this verse of the Qur’an. (at-Tabari)
Emerick, Yahiya. The Meaning of the Holy Qur’an in Today’s English (p. 829). Unknown. Kindle Edition.