Water; Its Purity and Impurity

There is also no harm in performing ablution with used water. When The Prophet صلى الله عليه وعلى آله وسلم performed ablution, people would take the leftover water from his ablution to perform their own. If a person performs ablution in a clean vessel, there is no harm in someone else using that water for ablution. However, water used to wash clothes, to wash after major impurity (ghusl), or to remove impurities should not be used for ablution.