Consider the following Hadith. Sunan of Abu-Dawood: Hadith 101 Narrated by: AbuHurayrah “The Messenger of Allah (peace be upon him) said: The prayer of a person who does not perform ablution is not valid, and the ablution of a person who does not mention the name of Allah (in the beginning) is not valid.” A person told me that the name of Allah is not to be recited in the toilet; not even before making Ablution. Now that I have realized my mistake, do I have to perform the Qada Salaats?
It is Mustahabb to take the name of Allah before making Wudhu. It is not a
pre-requisite for the validity of the Wudhu.
You do not have to make Qadhaa for the Salaats you performed without taking
the name of Allah before Wudhu.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai