The 'Awrah of the Muslim Woman in Front of the Muslim Woman

The Shaykh : It has occurred to me to remind our brothers present in this blessed session—if Allah wills—and those who will hear my words, of a matter that I think many Muslims are unaware of. It is not hidden from anyone that reminding people of what they are unaware of and ignorant of is more appropriate than filling their ears with matters they have long heard from preachers, teachers, and orators, as well as from radio broadcasts and similar means that Allah (Mighty and Majestic) has facilitated in this present age.
Since it was said by him (peace and blessings be upon him): there is no doubt that we take from this that the benefit to people lies in teaching them what they are ignorant of, or reminding them of what they are unaware of.
Of this nature is knowing what the 'awrah of the Muslim woman is in relation to the Muslim woman. For it is mentioned in some books of Islamic jurisprudence that the 'awrah of a woman in front of a Muslim woman is like the 'awrah of a man in front of a man; that is, from the navel to the knee. The meaning of this is that it is permissible for a Muslim woman to appear before her Muslim sister with her upper half, the upper half of her body, naked and uncovered; and likewise what is below her knees. What I want to remind you of is that we must know, above all, that this ruling has no evidence in the Book of Allah or in the hadith of the Messenger of Allah (peace and blessings be upon him and his family).