Two Saudi clerics have followed an Egyptian one in advocating breast-milk feeding as a way of establishing kinship between men and women, which would then allow the two to be in each others’ presence when the woman is alone and unveiled.
The things driving this legal advice or fatwa are first of all that Saudis mostly practice the Wahhabi form of Islam and people in the Arabian Peninsula generally tend to be more strict about the notion of gender segregation. Segregating women from unrelated males and having them veil when they go out of the house is not in the Qur’an and historians think they are customs adopted into early Islam by the Arab aristocracy from the Byzantines and ancient Iranians. The Qur’an just says a woman should cover her charms (zinah), and I suspect women in ancient pagan Arabia, where it is very hot, went about as those in some parts of subsaharan Africa still do, with very little clothing on, and the Qur’an just wanted them to cover up a bit. There is no mention in it of a face veil or even headscarf per se. And the only mention of anything like seclusion concerns the Prophet’s wives, and cannot be taken to refer to all Muslim women (in fact early Muslims would have probably thought it blasphemous to put ordinary women in that legal category).
Most Muslim women in history never veiled or were secluded. Pastoral nomads were a significant proportion of most Middle Eastern societies, and their women rode camels and horses outside during migrations to where the pasturage popped up. And peasant women worked the fields and could not be secluded or mostly afford to veil. Only in the past two centuries has veiling and sometimes seclusion been adopted in some Muslim countries as a sign of upward mobility (since these were aristocratic customs they are ways of putting on airs if you bet better off some year).
Since the Saudi religious authorities are so worried about secluding women, they are inevitably also worried about the ways in which contemporary societies and economies increasingly make such practices (which were only practical in the past for the very rich anyway) impossible.
Thus the appeal to “milk kinship.” Now, milk kinship is in fact a social institution in premodern Muslim societies, but it was not typically appealed to with regard to loosening gender segregation (which anyway was not so common in the medieval period). Where upper-class families had a nanny she might breastfeed the aristocratic baby at the same time that she breastfed her own infant, and that practice was considered to make the children a kind of sibling. Then the aristocratic could never take the daughter of his nanny to wife, and he might give special promotions or patronage to his ‘milk brother,’ the nanny’s son. These customs existed everywhere from Iran to Senegal, though they affected a small sliver of Muslim society.
I don’t always recommend a wiki article, but this one , which compares milk kinship in Islam to god-parenting in Christianity, is pretty good if not well sourced.
If you weren’t religious or weren’t Wahhabi, you could just suggest that strictures on women and men mixing socially are hidebound and more customary than Islamic, and just change the practice. Hundreds of millions of modern Muslims practice gender mixing (Saudi Arabia, which Westerners often misunderstand as having a normative Islam, is viewed by most Muslims as an outlier). In fact, the spread of the headscarf in places like Egypt is probably not a sign so much of increased female conservatism but an attempt to make it all right for women to enter the public sphere in much greater numbers (also women wearing headscarfs are a little bit less likely to be pinched and harassed by men in public). But such an argument would not work in Saudi Arabia, where the authorities are zealous about Wahhabi tradition.
Gender segregation is not only a practice of conservative Muslims. It is also in more rigid strains of Orthodox Judaism in the US and Israel; in the US, Orthodox schoolboys objected to having a woman bus driver, and in Israel Orthodox women are expected to sit at the back of the bus (one refused and was beaten).
Actually, gender segregation is quite common in Asia and I can remember it being difficult for a woman in India who had been elected to the board of a village NGO to meet with her male colleagues.
So the Saudi clerics are tinkering with the tradition, since in the past it concerned a wetnurse and children under 5, not adult women and adult men. And when that change is made, it becomes weird. But it isn’t a sign of conservatism (it departs from the traditional custom into new territory). It is a sign of modernism. It is an attempt to create a wider circle of men with whom women can legitimately interact in public.