Answered by Shaykh Faraz Rabbani
From the translation of Maliks Muwatta Book 2 Number 2.2.9
THe Messanger of Allah, may Allah bless him and grant him peace, said “When you wake up from sleep to pray wash your hands before you put them in wudu water for you do not know where your hands have spent the night.”
Questions –
1. If you forget and place your hands in water is that water unclean?
2. or you touch something which is wet and that is now unclean? and everything you touch with the now wet hand is unclean?…
Walaikum assalam wa rahmatullah,
I pray that this finds you well, and in the best of health and spirits. May Allah grant you all good and success in this life and the next.
According to the vast majority of the hadith commentators and fuqaha, this Prophetic command is for recommendation; and if one does place one’s hands in the water before washing them the water isn’t rendered filthy–unless one has established certainty that there was actual filth on one’s hands. [Kandahlawi, Awjaz al-Masalik `ala Muwatta’ al-Imam Malik; Ibn al-Humam, Fath al-Qadir]
And Allah alone gives success.
Faraz Rabbani