What is the benefit of mentioning the restriction "in your guardianship" (fi hujurikum) in the noble verse, given the consensus of the madhahib (schools of thought) on the prohibition of the stepdaughter (rabbibah) whether or not she is in the husband's guardianship?

The majority of scholars and the four Imams hold the view that the restriction "who are under your guardianship" is not to be taken literally, and that it was mentioned in the context of what is generally the case. They maintain that marrying a stepdaughter is forbidden for her mother's husband, whether she is under his guardianship or not, contrary to the view of the Dhahiris. Their evidence is that this restriction was mentioned either to strengthen the reason for the prohibition or for emphasis, and that the prohibition of marrying a stepdaughter is general and applies in all situations. They cited the hadith of Umm Habibah, in which the Prophet, peace and blessings be upon him, clarified that the prohibition of marrying a stepdaughter does not require her to be under one's guardianship. There is another opinion, held by the Dhahiris and others, that a stepdaughter is only forbidden if she is under the man's guardianship, which is an unusual opinion narrated from Ali ibn Abi Talib.