Abu Karayb, Muhammad bin al-'Ala' محمد بن العلاء - أبو كريب · The Book on Purification

Allah's Messenger said: "If it were not that it would be difficult on my nation, then I would have ordered them to use the Siwak for each prayer."

"The Prophet performed Wudu one time (for each limb)."

"The Prophet performed Wudu two time (for each limb)."

"The Prophet passed by two graves. He said: 'These two are being punished. And they are not being punished for something major. As for this one, he would not protect himself from his urine. As for this one, he used to spread Namimah (slander).'"