ANSWER:

You should say the bismillah in your heart without moving your lips when in the bathroom that’s attached to the toilet. 

Even if you don’t say it, your wudu is still valid. 

I hear a shiekh say that one should say Bismillah silently in the bathroom but for some reason, I still had doubts so before making wudu I would say the bismillah so I could slightly hear it and then I would say it silently the immediately begin wudu. Now I have no doubts but did this affect the validity of my wudu?

Ablution (Wudhu) | January 14, 2019 5:58 pm
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If a lady at home, makes fresh wudu in Fajar, then puts on normal fabric socks n she does not wash her feet with other prayers, due to winter. Some say it’s permissible if you are traveling but not in home situations, ppl say yes you can go without washing your feet for 24hrs max with socks on, normal fabric socks not necessarily leather socks in home or travelling both. What do you say please?
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Is there any authenticity of the belief that Wudu in Winter has extra rewards?