I say, and with God's success: The intended meaning of the obligation in washing is the practical obligation, that is, the duty that is preferable to perform rather than to neglect, with the prohibition of neglecting it, which is established by a conjectural evidence that has some ambiguity; because the obligations of washing are established by a hadith, which is a single report, and it does not establish the doctrinal obligation, which is preferable to perform rather than to neglect, with the prohibition of neglecting it, which is established by definitive evidence without any ambiguity. And God knows best.