Al-Ahzab (The Armies of Enemies)
Surah 33 · Verse 4
Allah has not made for any man two hearts inside him, and He has not made your wives, whom you orally declare to be your mothers, your (real) mothers, and He has not made, those whom you adopt as sons, your (real) sons. Those are (just) statements from your mouths and Allah speaks the truth and He guides to the (right) way.
A medical fact is confirmed that a man has only one heart. Islam is a realistic religion, it does not permit falsehood. Wives do not become mothers by oral declaration, mothers are only those who have given birth to us 58:2. Similarly adopted sons are not real sons, they should be called by their father’s name.
