Madmadah and Istinshaq - essential or not?

A: Madmadah and Istinshaq were authentically reported to have been done and stated by the Prophet (peace be upon him), and are included in washing the face. If a person omits one or both of them, their Wudu' is invalid. It is better not to separate them, as this was authentically reported from the Prophet (peace be upon him).