The sex of the embryo is not limited to the 120 days. It is determined on the 40th day.

It is the soul that is breathed in on the 120th day.

I have M.A in Biology. I am working in embryology lab and I am a religious person. Recently someone asked me: How in Islamic belief, in 120 days it is decided the sex of a child, when in early stage of embryo development we can see the sex of a child (couple of days)? I was embarrassed because I did not know the answer.

Medicine and medical treatments | September 18, 2014 2:30 am
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In an answer to a question you told that one can perform ruqya on himself to cure illness. I recently fell and hurt my leg, about a month ago. The pain hasn’t gone away. So, can I perform ruqya and wipe my hands over the parts that hurt me?
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My wife’s doctor has advised her to either sell or donate some of her reproductive eggs, due to a health issue that could lead to death. Is it permissible to either sell or donate those eggs.