Mujahid bin Jabir مجاهد بن جبر · The Book on Purification

Allah's Messenger said: "The key to Paradise is Salat, and the key to Salat is Wudu'."

"The Prophet prohibited us from facing the Qiblah while urinating. Then i saw him facing it a year before he died."

"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).'"